In the midst of the plentiful fan theories about the events and characters of Star Wars: Episode VII - The Force Awakens, there was still the lingering mystery about that creepy collection of dust that Kylo Ren places his mask — or as Poe Dameron would call it, his "apparatus" — on top of during the interrogation of Rey.
Speculation has varied from it being the ashes of his grandfather Darth Vader, to the much lighter option of a litter box for General Hux's cat Millicent, as Lucasfilm Story Group member Pablo Hidalgo joked on Twitter:
But in a recent interview with EW, director J.J. Abrams unveiled the truth:
"That table has the ashes of the enemies he’s killed. That moment was actually shot for, and meant to be used in, the scene where he was talking to the Vader mask.
"He originally had his mask off the first time we shot that scene. Then we reshot it with his mask on, but we had that shot which I loved and thought was so cool of the mask being slammed down into that ash. So that shot was stolen from the scene that we had changed and put into the scene with Rey.”
Quite a degree darker than a litter box. It seems like anyone thinking that Kylo Ren wasn't as hardened as he wanted people to believe might want to reconsider, lest they join that horrific pile of remains.
Source: Entertainment Weekly