I work as a data entry clerk in a manufacturing plant and need a manager to review the data before I can enter it in a program on the computer but he takes forever to do so most days so I am stuck with nothing to do until he is done (which btw, he doesn't usually tell me he is done reviewing…)
When I do eventually get the data needed and get it all entered, I spend the rest of my time literally just on my phone or on reddit.
One of the reasons why I wish the work week was shorter so I don't have to spend majority of my days rotting at my desk doing basically nothing.