Slightly simpler is:
Code:
Sub CellMerge()
Application.ScreenUpdating = False
Dim Tbl As Table
For Each Tbl In ActiveDocument.Tables
With Tbl.Rows(1)
If .Cells.Count > 2 Then
ActiveDocument.Range(.Cells(2).Range.Start, .Cells(3).Range.End).Cells.Merge
End If
End With
Next
Application.ScreenUpdating = True
End Sub
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