One of the best products ever invented is probably the Electric Grounding Bar. I used it to 'piggyback' all ten of the wires into two. The two wires will connect to the lead wires in the ceiling. The grounding bar is screwed into the junction (ceiling) box bottom as pictured below. I placed the bars close enough to the lamp cords but far enough away from each other as not to create a short. The corded lamp wire is poking through the pre-drilled holes. (Refer to Step 3 where you drilled the box bottom wire holes.) You will be bringing each of the ten lamp wires through the pre-drilled holes in the box's bottom.