BAW
   The following macros will do what you need, if I understand you
correctly.  I assumed your table 1 is starting in Column A, with headers in
row 1 and data starting in row 2.  I also assumed you table 2 is starting in
Column D with headers in row 8 and data starting in row 9.  You will need to
change the code to match your layout.
If you wish, send me an email, identifying yourself as BAW, and I'll send
you the small file I used for this.  HTH  Otto
Option Explicit
Dim RngListOfVolNums As Range
Dim RngListActivities As Range
Dim i As Range
Dim k As Range
Dim RngOfActivitiesNums As Range 'Rng of numbers to right of the activities
list
Dim FoundNum As Range

Sub GetActivites()
   Call GetRngs
   Call GetActivityNums
End Sub

Sub GetRngs()
   Set RngListOfVolNums = Range("A2", Range("A" & Rows.Count).End(xlUp))
   Set RngListActivities = Range("D9", Range("D" & Rows.Count).End(xlUp))
End Sub

Sub GetActivityNums()
   For Each i In RngListActivities
       If Not IsEmpty(i.Offset(, 1)) Then
       Set RngOfActivitiesNums = _
           Range(i.Offset(, 1), Cells(i.Row, Columns.Count).End(xlToLeft))
           For Each k In RngOfActivitiesNums
           Set FoundNum = RngListOfVolNums.Find(What:=k.Value,
LookAt:=xlWhole)
           If IsEmpty(FoundNum.Offset(, 2).Value) Then
               FoundNum.Offset(, 2).Value = i.Value
           Else
               FoundNum.Offset(, 2).Value = _
                   FoundNum.Offset(, 2).Value & _
                   ", " & i.Value
           End If
           Next k
       End If
   Next i
End Sub

Oops, my email address is ottokmnop@comcast.net.  Remove the "nop" from this
address.  Otto