There is usually a belt on the bed in a hotel room. Why?

It is used to sit on the bed, so as not to dirty the sheets.

This is called the bed end towel, or the main function of the bed end pad is to look beautiful. Hotel bedding is often pure white, with this bedside towel, it can look more high-end domineering. Another function is similar to that many years ago, a big towel was laid by the bed at home to make people sit on it, instead of directly sitting on the bed to make the owner uncomfortable.