Hello Gilles,
you can use another way to realize that. Use this approach from here and your action sub routine could looks like this:
'-Sub Action------------------------------------------------------------
Sub Action(session)
Dim vertScrollBar, cntScrollDown
Set vertScrollBar = session.findById("wnd[0]/usr").VerticalScrollbar
vertScrollBar.Position = vertScrollBar.Minimum
cntScrollDown = CStr(0 - Int(0 - (vertScrollBar.Maximum / vertScrollBar.Range)))
WScript.Echo cntScrollDown
End Sub
We get the object of the vertical scroll bar, set its position to the minimum and calculate how often the key down button must pressed to reach the end of the table. In my example I tried it with the TAC SE16.
Maybe not so elegant, but you get the information you need.
Best regards
Stefan