On my last foray into Cambridge, several different people (locals) highly recommended "Kay's Country Kitchen" at the airport. People who have private planes often do "fly-ins" there for lunch apparently. It may be more like "diner" type food but it might be worth a look. Prices should be reasonable. I've not been there but may get an opportunity to do so between now and May 3.

Also good is Bistro Poplar, in Cambridge. According to their website, entrees run about $20-22. Again, I've not been there.
http://www.bistropoplar.com/

If we want to go up to Easton for a nicer dinner, Mason's Gourmet restaurant in Easton is very nice. They have an expensive menu, also a "bistro" menu with lighter fare. I had an oyster pot pie there that was delicious! They also do lunch there, and have a great bar/deli area. And they make their own chocolates there. Hmm we should ride over there from Cambridge on Sat for lunch, coffee and chocolate. Then ride back to Cambridge and go kayaking. Or not.

http://www.masonsgourmet.com

Martha