Floor 341 was the location of the captain's quarters aboard Red Dwarf.
Whilst on probation from the Tank, Arnold Rimmer tended to a sick captain. Exiting the quarters, Rimmer made an enemy of the Chocolate Dispenser in the corridor outside when he attempted to steal from it, and the machine alerted the captain.
Much later, as the ship had been evacuated and was on flames due to the Chameleonic Microbe, Kryten scavenged the technologies of Z Deck, making a Prism Laser in the captain's quarters. Rimmer went through first.
Rimmer found himself back here again as he exited the Mirror Universe, only to find the others were gone. The Chocolate Dispenser mocked Rimmer, since the antidote had actually turned into the formula for the virus. It then shot a can out at Rimmer's head with some force.
Rimmer was approached by the Grim Reaper, but Rimmer kicked him in the crotch and ran off down the flaming corridor. (Only the Good...)