This pattern is used to list a few actions out of a bigger listing, performed in a given period of time.
わたしは 日よう日に さんぽを したり、本を よんだり します。
On Sundays, I do things like going for walks and reading books.
学生たちは いま ギターを ひいたり、うたったり して います。
The students are now doing things like playing the guitar and singing.