The upper cable operates the double-decker wobble checker and the lower one operates the stump-thumper dumper jumper.
When you find out what they're really for, let us know. That is, if they're not part of the linkage between lever and adjustment mechanism. I'd have a look under my seat but I burst a blood vessel each time I put it back because it's such a tight fit ever since it was reupholstered.
Christian