(Fairly) reusable edit cell that commits on loss of focus on the text field. Overriding the commitEdit(...) method is difficult to do without relying on knowing the default implementation, which I had to do here. The test code includes a key handler on the table that initiates editing on a key press.

EditCell.java

import javafx.event.Event;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableColumn.CellEditEvent;
import javafx.scene.control.TablePosition;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.util.StringConverter;


public class EditCell<S, T> extends TableCell<S, T> {

    // Text field for editing
    // TODO: allow this to be a plugable control.
    private final TextField textField = new TextField();
    
    // Converter for converting the text in the text field to the user type, and vice-versa:
    private final StringConverter<T> converter ;
    
    public EditCell(StringConverter<T> converter) {
        this.converter = converter ;

        itemProperty().addListener((obx, oldItem, newItem) -> {
            if (newItem == null) {
                setText(null);
            } else {
                setText(converter.toString(newItem));
            }
        });
        setGraphic(textField);
        setContentDisplay(ContentDisplay.TEXT_ONLY);

        textField.setOnAction(evt -> {
            commitEdit(this.converter.fromString(textField.getText()));
        });
        textField.focusedProperty().addListener((obs, wasFocused, isNowFocused) -> {
            if (! isNowFocused) {
                commitEdit(this.converter.fromString(textField.getText()));
            }
        });
        textField.addEventFilter(KeyEvent.KEY_PRESSED, event -> {
            if (event.getCode() == KeyCode.ESCAPE) {
                textField.setText(converter.toString(getItem()));
                cancelEdit();
                event.consume();
            } else if (event.getCode() == KeyCode.RIGHT) {
                getTableView().getSelectionModel().selectRightCell();
                event.consume();
            } else if (event.getCode() == KeyCode.LEFT) {
                getTableView().getSelectionModel().selectLeftCell();
                event.consume();
            } else if (event.getCode() == KeyCode.UP) {
                getTableView().getSelectionModel().selectAboveCell();
                event.consume();
            } else if (event.getCode() == KeyCode.DOWN) {
                getTableView().getSelectionModel().selectBelowCell();
                event.consume();
            }
        });
    }
    
    /**
     * Convenience converter that does nothing (converts Strings to themselves and vice-versa...).
     */
    public static final StringConverter<String> IDENTITY_CONVERTER = new StringConverter<String>() {

        @Override
        public String toString(String object) {
            return object;
        }

        @Override
        public String fromString(String string) {
            return string;
        }
        
    };
    
    /**
     * Convenience method for creating an EditCell for a String value.
     * @return
     */
    public static <S> EditCell<S, String> createStringEditCell() {
        return new EditCell<S, String>(IDENTITY_CONVERTER);
    }
    

    // set the text of the text field and display the graphic
    @Override
    public void startEdit() {
        super.startEdit();
        textField.setText(converter.toString(getItem()));
        setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
        textField.requestFocus();   
    }

    // revert to text display
    @Override
    public void cancelEdit() {
        super.cancelEdit();
        setContentDisplay(ContentDisplay.TEXT_ONLY);
    }

    // commits the edit. Update property if possible and revert to text display
    @Override
    public void commitEdit(T item) {
        
        // This block is necessary to support commit on losing focus, because the baked-in mechanism
        // sets our editing state to false before we can intercept the loss of focus.
        // The default commitEdit(...) method simply bails if we are not editing...
        if (! isEditing() && ! item.equals(getItem())) {
            TableView<S> table = getTableView();
            if (table != null) {
                TableColumn<S, T> column = getTableColumn();
                CellEditEvent<S, T> event = new CellEditEvent<>(table, 
                        new TablePosition<S,T>(table, getIndex(), column), 
                        TableColumn.editCommitEvent(), item);
                Event.fireEvent(column, event);
            }
        }

        super.commitEdit(item);
        
        setContentDisplay(ContentDisplay.TEXT_ONLY);
    }

}

TableViewEditOnType.java

import java.util.function.Function;

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TablePosition;
import javafx.scene.control.TableView;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;


public class TableViewEditOnType extends Application {


    @Override
    public void start(Stage primaryStage) {
        
        TableView<Person> table = new TableView<>();
        
        table.getSelectionModel().setCellSelectionEnabled(true);
        table.setEditable(true);
        
        table.getColumns().add(createColumn("First Name", Person::firstNameProperty));
        table.getColumns().add(createColumn("Last Name", Person::lastNameProperty));
        table.getColumns().add(createColumn("Email", Person::emailProperty));
        
        table.getItems().addAll(
                new Person("Jacob", "Smith", "jacob.smith@example.com"),
                new Person("Isabella", "Johnson", "isabella.johnson@example.com"),
                new Person("Ethan", "Williams", "ethan.williams@example.com"),
                new Person("Emma", "Jones", "emma.jones@example.com"),
                new Person("Michael", "Brown", "michael.brown@example.com")
        );
        
        table.setOnKeyPressed(event -> {
            TablePosition<Person, ?> pos = table.getFocusModel().getFocusedCell() ;
            if (pos != null && event.getCode().isLetterKey()) {
                table.edit(pos.getRow(), pos.getTableColumn());
            }
        });
        
        Button showDataButton = new Button("Debug data");
        showDataButton.setOnAction(event -> table.getItems().stream()
                .map(p -> String.format("%s %s", p.getFirstName(), p.getLastName()))
                .forEach(System.out::println));

        Scene scene = new Scene(new BorderPane(table, null, null, showDataButton, null), 880, 600);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private <T> TableColumn<T, String> createColumn(String title, Function<T, StringProperty> property) {
        TableColumn<T, String> col = new TableColumn<>(title);
        col.setCellValueFactory(cellData -> property.apply(cellData.getValue()));
        
        col.setCellFactory(column -> EditCell.createStringEditCell());
        return col ;
    }

    public static class Person {
        private final StringProperty firstName = new SimpleStringProperty();
        private final StringProperty lastName = new SimpleStringProperty();
        private final StringProperty email = new SimpleStringProperty();
        
        public Person(String firstName, String lastName, String email) {
            setFirstName(firstName);
            setLastName(lastName);
            setEmail(email);
        }

        public final StringProperty firstNameProperty() {
            return this.firstName;
        }

        public final java.lang.String getFirstName() {
            return this.firstNameProperty().get();
        }

        public final void setFirstName(final java.lang.String firstName) {
            this.firstNameProperty().set(firstName);
        }

        public final StringProperty lastNameProperty() {
            return this.lastName;
        }

        public final java.lang.String getLastName() {
            return this.lastNameProperty().get();
        }

        public final void setLastName(final java.lang.String lastName) {
            this.lastNameProperty().set(lastName);
        }

        public final StringProperty emailProperty() {
            return this.email;
        }

        public final java.lang.String getEmail() {
            return this.emailProperty().get();
        }

        public final void setEmail(final java.lang.String email) {
            this.emailProperty().set(email);
        }
        
        
    }

    public static void main(String[] args) {
        launch(args);
    }
}