Kind of looks like the wires for the fuel pump, not to sure if they should all be brown, brown is normally ground, and for the pump to run it would need a feed from the pump relay and a ground.

As for the other wires near by, they should be for the fuel gauge sender in the tank.

Best to have a word with Mr Haynes manual, if you dont have one then drop me a line and I will take a look at mine

Cheers

Rich