There's nothing, really, at 635 and Beltline specifically, other than fast food places like McDonalds, Jack, Jimmy Johns and maybe a Taco Cabana. A little down the road to the east at 635 and Mac, there are a lot of choices:
-- Razoos
-- Chilis
-- BWW
-- On the Border
-- Cheddars
-- Mi Cocina
-- Jasons
-- Saltgrass
-- Twin Peaks
-- Il fratelli (sp?; local italian place but nice interior)
And of course, things like Texadelphia, Firehouse, Chipoltle and Freebirds.
The Keg and Taco Diner are south at 114 and Mac along with Red Hot and Blue, Dickies, Chammps (big sports bar). Via Real is way south on MacArthur between North Lake College and MacArthur HS. I don't recommend the place, but a lot of people like it. Trendy groupthink if you ask me, but whatever.
If you're going to go there, go to Po Melvins at Beltline and Walnut HIll in Irving. Sort of a mixture between a down home and Cajun place. Generous portions and pretty good food. It is about 3-4 miles south of 635 on Beltline.