Looking for casual place near Jiffy Lube Live concert pavillion
Right in Gainesville, there are several chains as sherriberry mentioned.
Mimi's Cafe in Virginia Gateway is reasonably good; there's also a Buffalo Wild Wings, a Chili's, and some other chains throughout the shopping center. If you are willing to drive a few miles down the road, there are two other shopping centers -- one with a Wegman's, which has a Bertucci's, and one with a Harris Teeter, which houses Eggspectation and Brooklyn Brothers Pizzeria.
2800 Clarendon Blvd, Arlington, VA 22201
923 Ellsworth Dr, Silver Spring, MD 20910
not near reston at all. Check out vagateway.com-this is a large shopping center very close to the pavillion. The website lists restos in the center. Nearby in Manassas, there is Cracker Barrell, Bob Evans, Uno Pizza, etc. Pretty much chain city. Even though these places are only a mile or so from the pavillion, with the traffic, you need to allow at least an hour from resto to concert as the venue is on a two lane road and traffic gets really backed up. Enjoy the concert but be prepared to wait 1-2 hours to get out of the parking lot after the concert. A picnic lunch would not be a bad idea. Keep in mind tailgating is not allowed at the venue and guests are not allowed to enter the parking lot more than 2 hours before the concert. (this policy is recent after several fatal car accidents following concerts there last year.)