test.cs

// convert a flat (non-nested) table to a JSON string
private string Table2Data(Table table, bool containsTableHeader) {

  // create a list of dictionaries
  var tableList = new List<Dictionary<string, string>>();

  // get the start row
  int startRow = containsTableHeader ? 2 : 1;

  // iterate through all rows
  for (int row = startRow; row < table.Rows.Count; row++) {
    // create a dictionary for each row
    var rowData = new Dictionary<string, string>();

    // iterate through all columns
    for (int col = 1; col < table.Columns.Count; col++) {
      // get the column title from the first row
      var columnTitle = containsTableHeader ? 
        table.Cells[1, col].Text.Trim('\t') : $"Column {col}";

      // add the cell text to the dictionary
      rowData[columnTitle] = table.Cells[row, col].Text.Trim('\t');
    }

    // add the dictionary to the list
    tableList.Add(rowData);
  }

  // return the JSON string
  return System.Text.Json.JsonSerializer.Serialize(tableList, new JsonSerializerOptions { WriteIndented = true });
}