You can walk in. Reservation or not you're still going to wait, they are never on time
I would advise making a reservation as well, but if you just want to grab a bite to eat during the week, and there's only two of you, you may be seated quickly to fill up one of the eight person tables they have.
Both! But it's highly highly recommend you make a reservation. I've had my reservation before and heard at times it can be up to 2 hrs to wait.
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