public partial class Form1 : Form
    {
        DataClasses1DataContext dc;
        public Form1()
        {
            InitializeComponent();
            dc = new DataClasses1DataContext();

            this.Load += new EventHandler(Form1_Load);
        }

        void Form1_Load(object sender, EventArgs e)
        {
            var dg = new DataGridView();
            dg.AutoGenerateColumns = true;
            dg.Size = new System.Drawing.Size(800, 600);
            dg.Location = new Point(10, 10);
            this.Controls.Add(dg);

            var b = new Button();
            b.Text = "Сохранить";
            b.Size = new System.Drawing.Size(100, 20);
            b.Location = new Point(10, 620);
            this.Controls.Add(b);

            b.Click += (s, e2) => dc.SubmitChanges();

            dg.DataSource = dc.Exercises;
        }
    }