Joop V.
Yelp
Bow Market is a nice neighborhood market that was quite recently opened in the past months in Union Square area. Unlike the rest if the neighborhood that this market is situated, Bow Market comes across as a hip, trendy place so worthy of cool people to hang out. The market itself isn't quite large, but does have a little bit of everything from food (coffee shops, breweries, macarons, pierogis, empanadas/pizzas, Korean and seafood popup, etc) along to crafts (cards, handmade shoes, soaps, magnets, clothing, etc). The vibe itself attracts late 20s to early 40s crowd and was very lively!
There are tables outside to hang out when the weather is pleasant as well. Most of the shops dont have any seayings inside though, so I'm not sure if they'd be open during the winter at all (or if they do..not sure where you may be able to sit). They also do have stand-up comedy shows that open in the evening/at night.
If you are in Somerville area, check this place out. You can browse the shops in less than an hour..or hang out with friends for a few hours or longer even!
Note: it's a little bit of a walk from the T to this place, but when the upcoming new T station opens at Union Square...I'm sure this place will be so popular among nearby neighbors/visitors