I recently got an Amazon Fire HD 8 tablet and for the most part it’s been running fine. However, I encountered a weird and annoying issue where, all of a sudden, I had what seem to be system/hidden apps showing up on my Home screen.
The apps in question were, IIRC, Device Setup, Downloads, Music, Kindle Store and maybe one more that I can’t find/remember.
The solution was to go to Settings → Apps & Notifications → Manage All Application → Home Pages → Storage. When there, tap Force Stop and Clear Data. That should get rid of the stray icons.