Baltimore wargame stores in 1980
In 1980, I had a job at a toy store in Columbia, MD that sold boardgames and RPGs, among many toys.  This store, Patowmack Toys, had a branch in Baltimore at the Inner Harbor Mall.  The name, I believe was "The Play is the Thing".  Neither store offered in-store play.

I don't recall any stores in Baltimore at that time offering in-store play.  Baltimore was a bit off my normal roaming ground, but I think I would have made an effort had I heard about such a store.