To be able to designate separate picklist options for addressee and salutation. It's rare an organization would use the same options for both, and yet they're all there in one big list. You can designate phone options as being for phone or email and only see those options when entering either type - you should be able to do the same for Addressee and Salutation.
This would be helpful. I see so many constituents that end up with incorrect Add/Sal entries because users are overwhelmed by the long dropdown list of options. Add & Sal really are two different things, so it makes sense for them to be separate tables.