Public Class Form1
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        WebBrowser1.Navigate("http://www.martintallett.com")
    End Sub
    Private Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim t As New TabPage
        Dim w As New WebBrowser
        t.Text = "TabPage" & TabControl1.TabPages.Count + 1
        w.Dock = DockStyle.Fill
        w.Navigate("http://www.google.com")
        t.Controls.Add(w)
        Me.TabControl1.Controls.Add(t)
    End Sub
End Class