Try:
Code:
Sub MergeAllTableRows()
Dim Tbl As Table, TblRw As Row
For Each Tbl In ActiveDocument.Tables
For Each TblRw In Tbl.Rows
TblRw.Range.Cells.Merge
Next
Next
End Sub
PS: Please don't resurrect old threads. I've split your post off to a new one, with a link back to the old one.