Hiya.
Pretty much nothing...unless paper clips and calculators count. I have tried to use my tablet at the table (when I was DM'ing Pathfinder or an adventure path I didn't have in printed format). Each time it was a massive PITA. I've had players try to use their tablet or smart phone to do stuff on, but they are still WAAAAAY to slow to be useful at the table. Writing down notes, drawing maps, sketching out diagrams...paper and pencil (or dry erase board) gets it done in seconds; takes minutes or more (if it's even possible) on a tablet/smartphone.
Laptops...too big, bulky and loud to even consider, really.
I do put on non-lyrical music on the TV for BG ambiance (usually Nature Sounds, Classical or something like that....but Techno/Dance for when we are playing super-heroes...classical country for western...whatever fits the current game).
^_^
Paul L. Ming