(1) Jump down and run to the left (that means *away* from the way to the exit). If you succeed in running around the behemoths then you have won. Your way will go up to a small room and then into a narrow corridor (beware of the holes in the floor!), which is unpassable for large creatures like behemoths. (2) Behind the narrow corridor aren't any creatures, you are safe there. Take your bow, lure some behemoths to the corridor, and shoot. The behemoths will fall in the end. Lure another set of behemoths to the corridor. Repeat. Until there are some behemoths in the hole.

Well, non-archers will need some time for killing all behemoths but the method is completely safe. The behemoths cannot pass the corridor, you can shoot on them from a safe distance.