//make sure the property value factory should be exactly same as the e.g getStudentId from your model class
studentId.setCellValueFactory(new PropertyValueFactory<>("StudentId"));
firstName.setCellValueFactory(new PropertyValueFactory<>("FirstName"));
lastName.setCellValueFactory(new PropertyValueFactory<>("LastName"));
//add your data to the table here.
tbData.setItems(FXCollections.observableArrayList(
studentList
));