i go to indy about 2-3 times a year, but i'm always working when i'm there so i usually only am able to get fast food. There is a Mall attached to the convention centerwhich has a nice food court. all of the attached hotels all have resturants.
Within walking distance is a Hard Rock Cafe, Hooters, Tilted Kilt, RAM restuarant (pretty expensive), St. Elmo's steak house (very expensive), Steak and Shake, California Pizza Kitchen, and there are many other's i'm sure i missed.
When i'm there for work I ususally only eat subway, because it's easy to get to and affordable.