Fine dining weekday lunch - Newton area
Need nice restaurant somewhat near Waltham Marriott; nicer restaurants seem to close for lunch
The Biltmore on Chestnut Street might work for you. Or you could go up Lexington Street into Moody and try Solea. There's a sweet little Italian panini place (I think it might be Bocca Bella or a name like that) on Lexington off Commonwealth that is about 5 blocks or so from the Marriott if you mean the one on the Charles River off Commonwealth.
Blue Ginger is not far and serves lunch. Kouzina is even closer and I have always enjoyed the lunch there -- I'm just not sure if they are still open for business.