Thank you again for the reply.
That essentially is what I have at the moment. I need something that will give me only the values that are in both Tab1 and Tab2.
For example if Tab1 has the value ‘A76’ but Tab2 does not then the masterPrac table should not contain ‘A76’.
Also if Tab2 has the value 'G29' and 'G29' is not in Tab1 then masterPrac should not contain 'G29'.