No stay at OTA is complete without a visit to Hard Times Cafe (
https://www.hardtimes.com/location/hard-times-alexandria/). Across King Street and maybe three blocks toward the river. Chili, burgers, wings, etc. They have salads but nobody goes to Hard Times for health food.
Bob and Edith's took over a place previously occupied by a not very good seafood place that never seemed to have any diners. We're better off now.
There used to be a couple of tapas places on lower King Street but I don't think they made it through Covid.
Never tried sushi/sashimi in Old Town. Our sushi place is Crystal Bonsai, one of about a dozen small restaurants on one block of 23rd Street in Crystal City (Arlington). If you make it there, Royal Pawn on the corner of 23rd St. and Eads has a great selection of jewelry, watches, guitars, etc.