Yet again a scan of the SLF FAQ's refer you to SeatGuru which provides many answers.
SeatGuru Seat Map Jet Airways Boeing 777-300ER (773)
PTV will be in the armrest. Very simple to operate - you fold it out. Your tray able will be in the arm rest too.
Look at SeatGuru to see if you've put yourself on an exit row, because there are three rows of bulkheads and only one is on an exit row. If you're on an exit row you'll find things a bit chilly, and the smell/crowds for the loos might be bothersome. Likewise if you've put yourself next to the galley you'll not get much peace and quiet.