DD, Reading Terminal Market is very cool. D’Nics has the best hot pork sandwich. The market, in general, is super cool. Also, if you are a beer fan, Monk’s Cafe has an awesome Belgian beer selection and their mussels are very good, if you go get the Mussles Ghent!
The area between EF and most hotels in the downtown area is sketchy. Philly, otherwise, is very walkable, especially all around the central downtown area.