i came up with this. i don;t know of a better way
Dim doc As New Aspose.Words.Document("C:\a\a.doc")
Dim ns As Aspose.Words.NodeCollection = doc.GetChildNodes(Aspose.Words.NodeType.Table, True)
For Each n As Aspose.Words.Tables.Table In ns
Dim rc As New List(Of Aspose.Words.Tables.Row)
Dim rc2 As New List(Of Aspose.Words.Tables.Row)
For i As Integer = 1 To n.Rows.Count - 1
Dim r As Aspose.Words.Tables.Row = n.Rows(i)
rc.Add(CType(r.Clone(True), Aspose.Words.Tables.Row))
rc2.Add(r)
Next
'Next
For i As Integer = 0 To 2
For Each rr As Aspose.Words.Tables.Row In rc
Dim newRow As Aspose.Words.Tables.Row = CType(rr.Clone(False), Aspose.Words.Tables.Row)
For Each c As Aspose.Words.Tables.Cell In rr
Dim newCell As Aspose.Words.Tables.Cell = CType(c.Clone(False), Aspose.Words.Tables.Cell)
Dim para As New Aspose.Words.Paragraph(doc)
newCell.AppendChild(para)
newRow.AppendChild(newCell)
Dim b As New Aspose.Words.DocumentBuilder(doc)
b.MoveTo(para)
b.Write("")
Next
n.Rows.Add(newRow)
Next
Next
For Each r As Aspose.Words.Tables.Row In rc2
n.Rows.Remove(r)
Next
Next
doc.Save("C:\a\a1.doc")