Selection.InsertCells (Word)

Adds cells to an existing table.

The number of cells inserted is equal to the number of cells in the selection. You can also insert cells by using the Add method of the Cells object.

InsertCells (ShiftCells)

ShiftCells: Specifies how to insert the cells into the existing columns and rows of the table.

If Selection.Cells.Count >= 1 Then 
 Selection.InsertCells ShiftCells:=wdInsertCellsShiftRight 
 For Each aBorder In Selection.Borders 
 aBorder.LineStyle = wdLineStyleSingle 
 aBorder.ColorIndex = wdRed 
 Next aBorder 
End If