@FXML
    TableView<Statistics> tableView;
    @FXML
    TableColumn<Statistics, Integer> colWeekNumber;
    @FXML
    TableColumn<Statistics, Double> colExerciseHours;



public class HandleStatistics {

    public void addStatistics(TableView<Statistics> tableView, TableColumn<Statistics, Integer> colWeekNumber, TableColumn<Statistics, Double> colExerciseHours) {
        colWeekNumber.setCellValueFactory(new PropertyValueFactory<Statistics, Integer>("weekNumber"));
        colExerciseHours.setCellValueFactory(new PropertyValueFactory<Statistics, Double>("exerciseHours"));

        tableView.setItems(getStatistics());
    }

    public ObservableList<Statistics> getStatistics() {
        ObservableList<Statistics> statistics = FXCollections.observableArrayList();
        statistics.add(new Statistics(46, 4.6));
        statistics.add(new Statistics(47, 5.8));

        return statistics;
    }


package Functionality;

public class Statistics {

    private int weekNumber;
    private double exerciseHours;

    public Statistics(int weekNumber, double exerciseHours) {
        this.weekNumber = weekNumber;
        this.exerciseHours = exerciseHours;
    }

    public void setWeekNumber(int weekNumber) {
        this.weekNumber = weekNumber;
    }

    public int getWeekNumber() {
        return weekNumber;
    }

    public void setExerciseHours(double exerciseHours) {
        this.exerciseHours = exerciseHours;
    }

    public double getExerciseHours() {
        return exerciseHours;
    }
}