It's a shopping and dining district with some other entertainment options. It's a fairly long walk from 1 side to the other (but a boat to get back fairly quick). If your just going to stroll through and back, I'd probably skip the dinner reservation. If your going to see cirque du soleil, bowling, etc etc you probably want to some food..
I generally just walk in somewhere and don't reserve anything. If it's a signature resturant that interests you, I would recommend the other way and come just in time to eat and enjoy DTD afterwards. It gets lively with music performances and things sprinkled around when the sun goes down. If your not looking to shop, this might interest you more than an afternoon stroll through it.