There is no way to determine whether the words you want to keep are different from the words you want to discard, when both are formatted as US English, as in your example. The only practical solution I can think of is to check against a predefined list, which is the solution adopted below. The error relates to the fact that your current example document has merged cells, which are more difficult to work with. However the following works with your example document. You can add words and/or phrases to the array if your tables have different combinations of strings in the cells.
Code:
Sub Macro1()
Dim vList As Variant
Dim oTable As Table
Dim oCell As Cell
Dim i As Long
Dim oRng As Range
Dim sText As String
Dim bOmit As Boolean
vList = Array("Goodwill", "Income", "Net Cost", "A") 'The words to ignore when they appear to the left of the '/' character.
Set oTable = Selection.Tables(1)
With oTable
For Each oCell In oTable.Range.Cells
Set oRng = oCell.Range
oRng.Case = wdTitleWord
If InStr(1, oRng.Text, "/") > 0 Then
sText = Split(oRng.Text, "/")(0)
If IsNumeric(sText) = False Then
bOmit = False
For i = 0 To UBound(vList)
If CStr(vList(i)) = sText Then
bOmit = True
Exit For
End If
Next i
If bOmit = False Then
oRng.Text = Trim(Split(oRng.Text, "/")(1))
End If
End If
End If
Next oCell
End With
Set oTable = Nothing
Set oRng = Nothing
End Sub