Sub ProcessTables()
Application.ScreenUpdating = False
Dim Tbl As Table
With ActiveDocument
  For Each Tbl In .Tables
    With Tbl.Range.Find
      .ClearFormatting
      .Replacement.ClearFormatting
      .Forward = True
      .Wrap = wdFindStop
      .Format = False
      .MatchCase = False
      .MatchWholeWord = False
      .MatchWildcards = False
      .MatchSoundsLike = False
      .MatchAllWordForms = False
      .Text = "^p"
      .Replacement.Text = "???"
      .Execute Replace:=wdReplaceAll
    End With
  Next
End With
Application.ScreenUpdating = True
End Sub