Please keep in mind that a 51 page paper sounds more like a thesis than an "average" essay. I think it is important to remember that most programs are structured differently. For instance, some have the first semester dedicated to in-class only and then the next semester full time practicum only, while others (like the one I'm in) are a mix. This will greatly influence what you can expect in terms of course load. Also, if your program requires a thesis, that is where you will get that monster 51 page paper--but remember, the rest of your schedule will be adjusted accordingly. You will NOT have 4 courses each requiring a 51 page paper.
In my program, I have 3 days of placement and 4 courses (total 33 hours not including reading assignments. etc.). There is a ton of reading and in most cases, you cant get away with not reading because you have to reference the readings in your weekly assignments. In the first semester, I've written eight major papers (10 pages ++) and several minor assignments (reflection pieces, etc.) Having a full course load AND placement has been challenging and there isn't a lot of spare time.
But, if you can prioritize well, you can still manage to have a social life. It cant be all school all of the time, you'll stress out.