For the past 3 yrs I have had an exchange student from Japan stay with my family for 2 weeks. We usually get scarves, cloth napkins, and assorted souvenirs.
The ones we have appreciated the most have been toys for the kids. One yr a student brought a little die cast mini of their family minivan - a hit with my kids. Some of the scarves, etc are not necessarily to my taste. I do remember when I travelled as a student, my mom equipped me with scarves and jewellery (trinkets). Dunno what my mom was thinking as those were hard to give as gifts - so individualized!
Old Bay seasoning is a good idea, a coffee table book about Maryland/U.S. would be a very nice gift. My students usually bring me pictures of their hometown and we love going through them. I would love a coffee table book

One made me a fairly extensive scrapbook of herself and her life and that was fun. it included pics of her home, her family, her school uniform, what typical meals were, typical daily schedule, her hobbies, etc.
Local cookbooks, what about Founding Father - type souvenirs? For me, coming from a different country, I'm thoroughly fascinated with the Founding Fathers, pioneer life, etc. Think Little House on the Prairie LOL! White House /DC type souvenirs would also be cool.
What about a bundle of little American gifts including a small coffee table book, some local foods (when I think Maryland, I think crab - so even a crab stuffie or something like that).