Adding data to Tableview JavaFX

Table.fxml

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="563.0" prefWidth="1102.0" xmlns="http://javafx.com/javafx/9.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="home.controllers.StudentsController"> 
<TableView fx:id="tbData" layoutX="20.0" layoutY="192.0" prefHeight="349.0" prefWidth="1066.0" stylesheets="@../css/fullpackstyling.css" AnchorPane.bottomAnchor="22.0" AnchorPane.leftAnchor="20.0" AnchorPane.rightAnchor="16.0" AnchorPane.topAnchor="192.0">
        <columns>
          <TableColumn fx:id="studentId" prefWidth="75.0" text="StudentId" />
          <TableColumn fx:id="firstName" prefWidth="75.0" text="First Name" />
            <TableColumn fx:id="lastName" prefWidth="75.0" text="Last Name" />
        </columns>
         <columnResizePolicy>
            <TableView fx:constant="CONSTRAINED_RESIZE_POLICY" />
         </columnResizePolicy>
      </TableView>
  </AnchorPane>