I JUST NOW discovered that you can break stuff in the environment like tables, cabinets, and furniture. (Cabinets sometimes drop components or Potions of Energy/Mending)
If you smash bookcases you’ll occasionally find special lore notes.
From the Game Guide Major Features:
“Destructible Environments give evidence of your massive battles as you kick through house doors, destroy furniture and smash crumbling walls to reveal secret passages.”
Best way to smash these items is either with ranged or hold Shift to attack with melee without moving.
Back in the very early days of testing some of these were almost harder to hit and break than killing a boss 
What does get confusung is that once you get used to what items will break, you then realise not every item of the same type etc will always break. Some of them don’t break whatever you do to them 
And some skills won’t break them like Devouring Swarm. Darned annoying when you have it on your LMB.
Yep, some cabinets don’t break, neither do beds or wash basins or bathtubs.