Given that the exact same question is the current top post but for driving instead of transit, I feel this question was needed.
My answer: I saw some guys hooking up a Raclette Grill to the outlet in an otherwise empty German intercity rail waggon. They had it unpacked in one of these 4 person seats with a small table. No idea if that could work or if draws too much power from the board net. I just headed on to the next waggon.
As I was preparing to get off the train, I heard the man next to me say “hublublublubluh”.
I looked over. He was lying down.
“hublublublubluh” he repeated, and this time I got to witness the exit of pints of beery vomit onto the floor.
The train stopped. The vomit rushed across the floor under other people’s feet and bags. As I got off I noticed the smell.
Really glad that was my stop.