With iOS 11 came a new feature that lets you save (potentially lots of) iPad or iPhone storage space. It’s called Offload Unused Apps. What it does is uninstall apps that you haven’t used in a long time, but it leaves all data associated with the app, as well as the app icon. When you want to use the app again, you tap on the icon to have it reinstalled.
To enable Offload Unused Apps, go to Settings > General > iPad Storage and tap Enable to the right of Offoad Unused Apps.
As you can see in my example, 12 gigabyte of storage could be reclaimed.