Exactly how far inset is the raised rail on most tables? I've seen a few where it's deeper under the rail and some where it's almost nearly flush with just the vinyl sticking past it. Is there a standard that people go by or any kind of consensus?
I prefer some overhang, but not much. Don't like having lean forward to dig underneath the rail (where I can't see) to retreive chips 'n stuff.
If you back off 1/2" or so, you won't compromise the wood edge integrity, and the foam/vinyl will extend roughly 1/2" beyond the wood rail edge (creating about a 1" or less total setback).
Some set it back further to allow ample room for stapling the vinyl underneath. A lot depends on your specific design.
If this is your first build, I'd make a couple of short (4"-6") sample rail test pieces to see what you like and what is easiest. Time well spent, imo.