Pucca,
First of all, before you get in line for the crabcake (and make sure you get the jumbo lump cake rather than the cheaper ones), belly up to the raw bar for a few dozen local oysters and clams on the half shell.
At several of the meat market stalls, one that comes to mind is Regan's Meats, you'll see various corned pork products in plastic bus tubs such as corned pork tails, sidemeat (fatback/streak o' lean), and possibly other cuts. These are traditionally used in the region for cooking greens or beans and according to friend of mine (a retired career Philadelphia hotel executive chef) , an essential ingredient in Philadelphia Pepper Pot soup.
Don't leave Baltimore without a good supply of scrapple and also Old Bay flavored Utz potato chips as well as Grandma Utz's chips (fried in pure lard). Pick up a few pounds of real jumbo lump crabmeat. There's a world of difference between the real stuff (perishable)and the canned pasteurized stuff (keeps for years) sold at Costco and everywhere else in town.
And don't forget to have a Baltimore style polish sausage sandwich at Pollock Johnnie's.