A family of Microsoft word processing software products for creating web, email, and print documents.
You don't say what you mean by "not working correctly". However, there is no need to insert a new row after the last row of the table. If the selection is in the last row of the table, the cells from the clipboard will be pasted after that row:
You could use the following to add the cells to the third table in the document
ActiveDocument.Tables(3).Rows(ActiveDocument.Tables(3).Rows.Count).Select
With Selection
.Collapse wdCollapseStart
.PasteAppendTable
End With