As mentioned, Ta-im is not vegan nor vegetarian, but they do have a few options for us and I went here numerous times the last time I was in Tokyo, because I simply fell in love with the place. It really felt like being at 'home'.
It's a small, cosy, little place - very nice and intimate, it feels like you are eating at someone's home. Dan, the owner and chef of Ta-im, is such a lovely, welcoming guy and he very helpfully told me about the veg options on offer. At lunch time there are 2 options, 1 vegan and 1 vegetarian. I've had both and they are delicious! A tasty soup to start off with, then falafel, hummus, warm pita (unlimited), red pepper dip and salad (you can also choose another lunch set that comes with an Israeli sweet for dessert; I personally wasn't fond of it, too sweet for my liking...but the rest of the food was superb). I have brought several friends here and they have all loved it and have commented on the comforting ambiance; my boyfriend who had never tried Middle Eastern food before really enjoyed the food and has since been back after I left Tokyo.
It is a bit pricey, but then this is Tokyo and Ebisu itself is a pretty expensive area. However, I love Ta-im, the atmosphere, the Israeli radio station playing, how at home Dan makes people feel there and the excellent quality of food there, so I am happy to pay :-) I can't wait to go back next time I'm in Tokyo.
Cons: A bit pricey