Can I annex fewer certificates for a shorter application? I want to apply at a German university for Computer Science. The instruction tells me to annex documents about additional qualifications.

So I decided for the ten most important and most related qualifications and awards I got and wrote an overview page for them. They are grouped by field and date, and there is a short description of about two lines for every qualification.

Now I need to annex the actual copies of the certificates. I feel uncomfortable with handing in ten copies, plus some other documents. I think providing the certificate for every qualification might result in too much pages which won't get read but make a negative impression.

Can I just provide a few of the copies and tell the University staff to ask for more if wanted?
It has been my experience that to not include a certified copy of each qualification at least can potentially result in unnecessary delays in processing your application.  Essentially, I have found that many universities frown upon incomplete applications.