I actually spent about a year working in Norwood before I found Lambert's and it appalls me how that happened given that I have to drive past it every night on the way home. And especially since I can walk there from work for lunch!
Lambert's is mainly a deli counter and fresh produce kind of grocery. No meat/fish section and some very small selections of stuff like pasta, baking goods and whatnot. What they do have though are a lot of specialty sauces/jams for marinades and whatnot such as Stonewall Kitchen jams and spreads. I use these jams for the baked brie :). And one last note that they sell freshly ground spices (which is a huuuuuge deal).
Also, for a hearty lunch (and possibly dinner because of leftovers!), Lambert's deli counter makes some extremely massive sandwiches. Maybe not on the level of Harold's New York Deli but they're still large enough anyway that one could easily chow down on half of the sandwich and save the other half for a nicely sized dinner. They also bake rotisserie chickens, spare ribs, and fresh calzones (The calzones are VERY hearty as well...oy!) as well as serving at least 6 different types of soup every day. And I need to mention the salad bar...one of the largest I've ever seen!