The Amazing Thai Taste Festival is a fantastic stop for foodies if you happen to be in Bangkok around this time! The festival has booths from all sorts of vendors: street food, restaurants, even a cooking school! And it has a stage with live cooking demo and performances (which was incredibly LOUD hence me yelling my way through this place! Sorry about that...).
It was actually not as big as I expected, which isn't a bad thing, because it means that you CAN realistically see everything in one evening. There are some seats and tables for eating there as well, but not much. It's hot though, so be prepared!
This year (2017) it took place at the Makkasan Airport Link station around mid June. I'm not sure if this is is an annual thing or a one-off, but you can check out the Tourism Authority of Thailand website and Facebook page for more info on festivals like this..