After an on-site interview, should I seek reimbursement for meal expenses that occurred to and fro the interview? They did give me a expense report so I know it is legit to fill it out but just not sure if this would give a bad impression.
I think it's pretty standard that "travel expenses" include all meals purchased from the time you leave home until your return.
Some institutions do meal reimbursement on a "per diem" basis, where you get a flat amount per day for meals, regardless of how much you actually spend. In some cases there is a slightly lower rate for the first and last day of your journey, reflecting the fact that you might have been at home for part of those days.
If you are unsure, you might get in touch with the administrative person in the department who handles travel reimbursements and ask them about their policies. This person is typically not involved with the hiring process, so there's no need to worry about making a bad impression.
Side comment: You are probably worrying about this a bit more than you need to. If you're on the job market, this is probably one of the first times you've had people paying your travel expenses, and it's normal to be a little sensitive about that. But paying travel expenses is a very standard part of academic life, and for the most part, the people paying for you are not going to notice these sort of financial details or let them affect their perception of you. It's just an academic chore for them, and it isn't their personal money you're spending! Just use your own best judgment, and unless you do something outrageous, like asking to be reimbursed for strippers and champagne, you'll be fine.
Some universities in the US base their reimbursement policies on the US Government policies:
A conservative approach is to ask for reimbursements for expenses while in the city of the interview. For example, I would not ask for reimbursement for taxi fare from your home/work to the airport or a meal eaten at the airport prior to departing for the interview. I would ask for taxi fare from the airport to the hotel and any meals eaten after you arrive. Similarly, on the return, I would ask for taxi fare from the hotel to the airport, but not from the airport to your home.