Ted,

Yes. Then only thing I would do differently is:

Sub Tbl_Add_ColumnsII()
Dim oTbl As Table
Dim oCol As Column
Dim lngSeq As Long
  Application.ScreenUpdating = False
  Set oTbl = Selection.Tables(1)
  
  lngSeq = 2 'Use 2 to insert row after each odd or even Column. Use 3 for every third, 4 for every fourth, etc.)
  'Set oCol = oTbl.Columns(lngSeq) 'For every odd Column
  Set oCol = oTbl.Columns(lngSeq + 1) 'For every even Column, or other sequence (e.g., every third, fourth, fifth etc.)
  Do
    oTbl.Columns.Add oCol
    On Error GoTo Err_Index
    Set oCol = oTbl.Columns(oCol.Index + lngSeq)
  Loop Until oCol.Index = oTbl.Columns.Count
  oTbl.Columns.Add oCol
lbl_Exit:
  oTbl.AutoFitBehavior wdAutoFitWindow  'Added GKM
  Exit Sub
Err_Index:
  If oTbl.Columns.Last.Index - oCol.Index = lngSeq - 1 Then
    oTbl.Columns.Add
  End If
  Resume lbl_Exit
End Sub