First, you might want to learn to correctly spell activities. I didn't think much of it while reading, but my browser has pointed out that every time you put it down, you spelled it wrong.
As far as narrowing them down...
1. Shadowing. It's important, but not so important that each physician needs to have his/her own slot. Just list the different specialties you shadowed and for how long, and anything in particular you learned.
2-4. Summer activities
5. Employment (assuming this wasn't one of your summer activities)
The rest is a little difficult to break down, since we don't know exactly what you did. Combining all the activities related to one research project is good (so, as someone else mentioned, if you did research, published, and then presented, put it all under one). Looks like you'd have 4 or so slots for that. Don't particularly care that you funded some programs, which leaves us with your Clubs and Volunteering.
I'd eliminate clubs that you don't have a vested interest in. For instance, I was a member of our school's Active Minds club, which was aimed at raising awareness of mental health problems in the university population. I even held two separate leadership positions, on account of one of my closest friends being the founder on campus. It sounded great on paper, but I found that I didn't participate in it as much as I would've liked, so rather than risk that being brought up in an interview, I just left it off my list. On the other hand, I participated a great deal in my school's RHA (though I didn't exactly hold a leadership position; I was merely the non-elected representative for my building), so I listed that, along with the awards and leadership positions I held there. So, in your case, if being President of the Pre-Med club was super important to you, list it. Otherwise, leave it off. So figure out 1-2 that are important to you, and put the rest under a leadership slot with bullets explaining your titles and duties.
By now, around 12 slots have been filled (assuming 4 research labs, 2 important clubs, and 1 club leadership). You have three more to work out your volunteer activities. I'd list all clinical volunteer activities together, and significant non-clinical activities together. If you only did a 4 hour gig as a part of your membership in the pre-med club, list it along with your leadership position in that club.
That leaves you with one slot to do with as you see fit. If one experience is so super important to you that you feel it needs its own place on your application, don't combine it with something else and put it in this extra slot.
