Can I delete a file from being shown in the 'recents' area of the Files iOS app?
No - you can't edit or suppress one item - just open new files and the one that's current will be less recent.
Yes - You can wipe all the items and start fresh.


Open the Files app. Go to Browse tab. You'll get a list of the Locations you've authorized Files to access: iCloud, Google, etc. Your Recents tab displays recently viewed files from any authorized drive - not just iCloud.

Tap the three dots "..." in the upper right hand corner of the screen and select "Edit" from the popup menu that will appear.  To clear the Recents view for any drive turn access off by tapping the Green Button. This clears the Recents view. You can then turn access back on by tapping the button again.  A little kluggy but it works.