If so what did those slaves do? What were their lives like?
Recently many colleges have been investigating their involvement with slavery and the slave trade. (Most of this research has been done by students themselves.) It's important to remember, though, that slavery wasn't confined to the South. Slavery also existed in the North during the colonial period, when many historic colleges were founded. And it's no surprise that most of the research being done in this area is in the North, as the South would prefer to ignore their involvement with slavery. However I was able to find one source in the South.
The involvement of colleges with slavery can be divided into four types: the slaves owned by the college who did labor for the college, the slaves owned by staff and faculty, the slaves owned by students, and the slaves who were distantly related to the funding of the college.
Specific to your question, this site from South Carolina College says that students were allowed to bring their own slaves to school until 1808. After that, the students paid a fee for the services of the campus's slaves.
Slaves did all of the sorts of duties that would today be done by a janitorial staff, such as cleaning the classrooms, offices, and chapels; plus things that today would be done by students or student-employees, such as cleaning laboratory glassware in the chemistry lab. Also, slaves did things required for living during that period, such as hauling water for washing and wood or coal for heating, emptying chamber pots, and tending animals like chickens and cows that were kept for milk and eggs, and horses kept for transportation. In addition, slaves cooked in the kitchen and served as waiters in the dining hall. When work was light, the college would hire slaves out to the local townspeople, and in several cases slaves were sold to fund the college.
Slavery was bad regardless of where you were made to work, but on college campuses it could be horrific. Imagine the fraternity culture of today and if those excesses of partying and hazing were combined with ownership of people. Slaves were often the targets of whippings and sexual assault, and dismemberment and branding were not unknown.
Finally, many college endowments came from wealth plantation owners who made money off the work of slaves, or from slave traders themselves.
You might be interested in reading Ebony and Ivy: Race, Slavery, and the Troubled History of America’s Universities by Craig Steven Wilder.
Sources:
http://www.harvardandslavery.com/wp-content/uploads/2011/11/Harvard-Slavery-Book-111110.pdf
https://columbiaandslavery.columbia.edu/content/1-kings-college-and-slavery
http://www.wm.edu/sites/lemonproject/researchandresources/historicaltimeline/index.php
https://www.nytimes.com/2016/04/17/us/georgetown-university-search-for-slave-descendants.html?_r=0
http://www.tuscaloosanews.com/news/20060407/slavery-marks-universitys-past