To clear contents of the tables, I think you have to use a for loop, accessing each cell. Something like this:
Code:
Dim t As Table
Set t = ActiveDocument.Tables(1)
Dim i As Integer, j As Integer
For i = 1 To t.Rows.count
For j = 1 To t.Columns.count
t.Cell(i, j).Range.Text = ""
Next j
Next i
You may not need this though. You could just use a template, or a dotx file. The original would always have a cleared table. However, the user-filled doc would need to be saved somewhere.