From what I know, during the festival of Saturnalia, (among other things) slave owners would provide table service to their slaves, and that in general, Slaves were seen as equals during the festival.
This has always seemed really strange to me, because usually when you think of slavery you think of all of the horrible connotations it carries, and not slave-owners making breakfast for their slaves.
Were they more amicable to each other? Or did they just do this because they just saw it as sort of a job that came with this particular festival?
More of course can be said, but our 'Slaves and Slavers' AMA might be of interest for you as it was fairly wide reaching in scope.