may not be 100% bullet proof but try this
Option Explicit
Sub Suffix()
Dim wsSuffix As Worksheet
Dim iLen As Long, iSuffix As Long
Dim r As Range, c As Range, r1 As Range
Dim sFrom As String, sTo As String, sOrig As String, sNew As String
'current in col A, replacement in colB
Set wsSuffix = Worksheets("Suffix")
'no cells selected
If Not TypeOf Selection Is Range Then Exit Sub
'make sure selection has text cells and just use them
Set r = Nothing
On Error Resume Next
Set r = Selection.SpecialCells(xlCellTypeConstants, xlTextValues)
On Error GoTo 0
'no text cells
If r Is Nothing Then Exit Sub
'just single cell
If r.Cells.Count = 1 Then
Set r1 = r
Else
Set r1 = Selection
End If
'loop suffixes then loop selection cells
With wsSuffix
For iSuffix = 2 To .Cells(1, 1).CurrentRegion.Rows.Count
sFrom = Trim(.Cells(iSuffix, 1).Value)
sTo = Trim(.Cells(iSuffix, 2).Value)
iLen = Len(sFrom)
For Each c In r1.Cells
sOrig = Trim(c.Value)
If Len(sOrig) = 0 Then GoTo NextCell
If Len(sOrig) < iLen Then GoTo NextCell
If Right(sOrig, iLen) <> sFrom Then GoTo NextCell
sNew = Left(sOrig, Len(sOrig) - iLen) & sTo
c.Value = sNew
NextCell:
Next
Next
End With
End Sub