In iOS 11 you can set your device to automatically delete apps to save space – while retaining settings and files in case you wish to later restore the app.
To activate it go to Settings, tap General and then tap iPad Storage. This will show a list of all your installed apps, ordered by how much storage space they’re consuming. Press any app that you haven’t used for a while and press Offload App.
This deletes the bulk of the app from your device, but keeps all documents, data, and saved games – so you won’t have to start from scratch if you want to get it back at a later date.
Offloaded apps will appear grayed out on your Home screen – to restore them, simply tap the icon.