There are at least four wheelchair accessible restaurants in Palmer Square, and the parking garage on Spring Street has a ramp out to the street. When I was in a wheelchair for foot surgery, my favorite place was Kristine's, which is a French bistro next to the public library. But there also is Witherspoon Grill, a white tablecloth steak house, next door. They are both in the library plaza, which is all flat with chairs and tables. Down the street on Hulfish is Mediterra, which serves tapas, and there's Teresa's Pizza on Palmer Square East. All of these restaurants have wheelchair accessible restrooms. There are other places too within a block of each other and most if not all of the shops are street level, though some are small and might be a bit tight for a wheelchair but the area is safe and you can leave the chair outside for a quick visit. The town is revamping part of Witherspoon to be one-way, and from what I can tell, this area will be wheelchair friendly also. You can spend a nice day just in the Palmer Square area, as u/ProfessorKnifey, says. Many people don't know this, but there is an original Norman Rockwell mural behind the bar in the Yankee Doodle Taproom. It's not in the best condition (and I am not recommending the food) but worth looking at. To get to it, use the Nassau Inn entrance across from Teresa's and take the elevator down. Good luck and enjoy your visit!