My error is that the table headers of my two tables are not shown. Right now I am setting the header with new JTable(data, columnNames).
Here is an example which shows, my problem:
public class Test extends JFrame {
    private static final long serialVersionUID = -4682396888922360841L;
    private JMenuBar menuBar;
    private JMenu mAbout;
    private JMenu mMain;
    private JTabbedPane tabbedPane;
    public SettingsTab settings = new SettingsTab();
    private void addMenuBar() {
        menuBar = new JMenuBar();
        mMain = new JMenu("Main");
        mAbout = new JMenu("About");
        menuBar.add(mMain);
        menuBar.add(mAbout);
        setJMenuBar(menuBar);
    }
    public void createTabBar() {
        tabbedPane = new JTabbedPane(JTabbedPane.TOP);
        tabbedPane.addTab("Settings", settings.createLayout());
        add(tabbedPane);
        tabbedPane.setTabLayoutPolicy(JTabbedPane.SCROLL_TAB_LAYOUT);
    }
    private void makeLayout() {
        setTitle("Test");
        setLayout(new BorderLayout());
        setPreferredSize(new Dimension(1000, 500));
        addMenuBar();
        createTabBar();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setVisible(true);
    }
    public void start() {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                makeLayout();   
            }
        });
    }
    public static void main(String[] args) {
        Test gui = new Test();
        gui.start();
    }
    public class SettingsTab extends JPanel {
        public JScrollPane createLayout() {
            JPanel panel = new JPanel(new MigLayout(""));
            JScrollPane sp = new JScrollPane(panel);
            sp.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
            panel.add(table1(), "growx, wrap");
            panel.add(Box.createRigidArea(new Dimension(0,10)));
            panel.add(table2());
            //          panel.add(Box.createRigidArea(new Dimension(0,10)));
            return sp;
        }
        public JPanel table1() {
            JPanel panel1 = new JPanel();
            String[] columnNames = {"First Name",
            "Last Name"};
            Object[][] data = {
                    {"Kathy", "Smith"},
                    {"John", "Doe"},
                    {"Sue", "Black"},
                    {"Jane", "White"},
                    {"Joe", "Brown"},
                    {"John", "Doe"},
                    {"Sue", "Black"},
                    {"Jane", "White"},
                    {"Joe", "Brown"}
            };
            final JTable table = new JTable(data, columnNames);
            tableProperties(table);
            panel1.add(table);
            panel1.setLayout(new BoxLayout(panel1, BoxLayout.Y_AXIS));
            return panel1;
        }
        public JPanel table2() {
            JPanel panel1 = new JPanel();
            String[] columnNames = {"First Name",
            "Last Name"};
            Object[][] data = {
                    {"Kathy", "Smith"},
                    {"John", "Doe"},
                    {"Sue", "Black"},
                    {"Jane", "White"},
                    {"Joe", "Brown"},
                    {"John", "Doe"},
                    {"Sue", "Black"},
                    {"Jane", "White"},
                    {"Joe", "Brown"}
            };
            final JTable table = new JTable(data, columnNames);
            table.setPreferredScrollableViewportSize(new Dimension(500, 70));
            table.setFillsViewportHeight(true);
            tableProperties(table);
            panel1.add(table);
            panel1.setLayout(new BoxLayout(panel1, BoxLayout.Y_AXIS));
            return panel1;
        }
        public void tableProperties(JTable table) {
            table.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS);
            table.repaint();
            table.revalidate();
        }
    }
}
Any recommendations what I am doing wrong?