Wow.... that'll take hours upon hours of complete repetitiveness. No thanks Bethesda.
The minor jobs don't take long at all. 10 minutes at most, if you know where to look for things. That is, unless you're not fast traveling.
EDIT: Did math... Point taken. Still, some jobs are shorter than others. If you do a sweep job and a (forget what it's called but where you steal 500 gold's worth of items) job in the same city, you can hit two birds with one stone, since the items in sweep jobs are plenty valuable. Always get two jobs at once and for the most part they'll end up in the same city.