It's possible. Really depends on how many credits you're taking and how many hours you'll be working. Also depends on how many hours you require to study and do well - that varies for everyone - and you won't really know until you start because DPT requires entirely different studying techniques than undergrad. And is it worth it - is the money worth it, do you enjoy the job, is it giving you more than it takes from you...time is very precious in DPT school.
I was working around 10 hours my first semester & it was fine. Then each semester I dropped more and more hours due to school demands, down to just two hours/week. Even that got to be a pain because I was just so busy with school, but I was doing it for both pay and really for a free gym membership. It also forced me to not be a student for a little while, which is a good thing...lol.
I also know a decent number of people in my program who maintain part-time jobs, ranging up to 20 hours/week (although I have no idea how on earth they manage that many hours, I personally would not be able to). Make sure that this job does not replace time that you will NEED for life balance - friends/family, sleep, exercise, food prep.....I know you're saying you don't have much else to do outside of school, but don't underestimate the need for time to maintain balance.
I think keep it, and if you just can't maintain it, then quit, just make sure of course you give them ample notice. Better than getting into the semester and realizing you could have handled work at the same time and really wish you still had the job but you quit.
Out of curiosity, what state is your school in?