Oh!
That one's fairly simple actually.
Code:
Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim page As New TabPage()
page.Text = "Untitled" ' This will be the default text for the tab (Similar to FF's Untitled new tab)
page.Name = "TabPage" + (tabControl1.TabCount - 0) ' So we can easily keep track of tabs based on index
Dim browser As New WebBrowser() ' Setup the controls to add
browser.Dock = DockStyle.Fill ' To make the browser fill to the tab page
browser.WebBrowserShortcutsEnabled = True ' To allow the standard IE shortcuts
page.Controls.Add(browser) ' Add the controls
tabControl1.TabPages.Add(page) ' Add the page to the tab container
End Sub
Each new control you want to add to the tab page, you need to add to the controls collection. (As shown above)
I think I commented the code enough to show what you need to do.