Enriching Event Contacts with LinkedIn Profile Matching

Hi friends .. I am trying to enrich a table of new contacts for an event we have in a specific city. However, I do not want to enrich those contacts that I already have enriched previously. I have a table with all my leads + emails and I know there is a lookup action in Clay. I am trying to set it up so that it uses linkedin profile to match contacts between both my tables and populate/create an email field with the matched contacts that already have emails. Can anyone help me with this? Thank you 🚀