This likely has already been asked here, but what the heck -- Chowhound rules don't discourage multiple threads on same subject and some new posters might not have answered in the older thread.
We go about 4-5 times a year. Last night, for the Reggae Festival, we packed our own picnic because it was easy to do some cooking and make turkey cutlet sandwiches with chimichurri sauce. Added some crunchy green beans from TJ's and some beers and that was that.
But on weeknights (we go on Wednesday to the Jazz series) we sometimes bring our food, though for Wynton Marsalis be ate at home before we left.
My seats are great (Section H, Row 1) but they aren't box seats with a table, so we don't like to eat food that requires a knife and fork -- too hard with the plate in our laps. We drive and park our own car and come from Culver City, so we head east on Culver/Venice then north on La Brea/Highland give or take a detour.
I think for our next show we're going to bring burritos from Pinche's on Culver. We looked at the menu during Eat LA and then saw some decent reviews here on CH. Burritos stay warm wrapped in foil and would be easy to eat at our seats. We've done sub sandwiches (Victor Jrs, among other places ), take out sushi (not my favorite as it gets sort of room temperature), pita sandwiches from Gaby's -- stuff like that.
But feel free not to limit your suggestions to my neck of the woods. Others might be interested in other neighborhoods.
In all seriousness, going to a show at the Hollywood Bowl is one of the great Los Angeles experiences. Tourists should consider this a must do, along with Disneyland and the beach. Tickets are reasonable, the venue is great and it's one of the few concert venues that allow you to bring your own meal inside.
All thoughts and suggestions are welcome.