A couple that come to mind are Oba! and Andina, both in the Pearl. My boyfriend's company has had biz lunches at both of those spots and they went over well. I have dined at both places a few times and the food and service are great.
Park Kitchen has a separate dining area. I was there for dinner the other night and a bunch of suits from Tillamook were there in the room. I only quickly glanced in so I'm not so sure about the size, though.