That’s the game at Fork:etc, a hip little prepared-foods café and grocery in Philadelphia. On Wednesday nights at eight, a random assemblage of foodies stroll in on a first-come-first-served basis to sit down for chef Thien Ngo’s ever-changing, communal-table dinner. (Think banana-flower salad, tapioca soup, and lobster maki rolls.) When he’s not improvising at Fork:etc on Hump Day, he’s commanding the kitchen next door at big brother — and highly lauded — Fork. Chef’s Bistro Dinner at Fork:etc, $40 for three courses, including wine. 308 Market St., (215) 625-9425,