Uso de tablas JTable. Crear, añadir y modificar.

Código Java (Main.java):

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;

public class Main extends JFrame {

    public Main() {

        String[] columnNames = {"Nombre", "Años", "Apto",};
        Object[][] datos = {
            {"Juan", 25, false},
            {"Sonia", 33, true},
            {"Pedro", 42, false}};

        DefaultTableModel dtm = new DefaultTableModel(datos, columnNames);
        final JTable table = new JTable(dtm);

        // Agregar nueva columna
        String[] columnaNueva1 = {"vago", "diestro", "normal",};
        dtm.addColumn("Tipo", columnaNueva1);

        // Agregar nueva fila
        Object[] newRow = {"Maria", 55, false};
        dtm.addRow(newRow);

        // Modificar celda especifica
        dtm.setValueAt("XXX", 3, 3); // Row/Col

        table.setPreferredScrollableViewportSize(new Dimension(250, 100));
        JScrollPane scrollPane = new JScrollPane(table);
        getContentPane().add(scrollPane, BorderLayout.CENTER);       
        addWindowListener(new WindowAdapter() {           
            public void windowClosing(WindowEvent e) {
                System.exit(0);               
            }
        });
       
    }

    public static void main(String[] args) {
        Main frame = new Main();
        frame.pack();
        frame.setVisible(true);
    }
   
}


Resultado: