is used to list multiple actions.
it can be translated as "Do things like (...), (...)".
It functions like 「や」, in that it also implies 'and other things like it', in that it is non-exhaustive.
映画を見たり、本を読んだり、昼寝をしたりする I do things like watching films, (and) reading books, and taking naps (and others not listed.).
本を読んだり、絵を描いたりする I read books and draw pictures (and others not listed.).
温泉に行ったり、すしを食べたりしました I went to the hot spring and ate sushi (and others not listed.).