How do I make the best of a busy resume?

I'm looking for jobs in one of two fields: technical writing, and Excel/VBA development. My work history has many examples of both, mostly short-term contract or freelance jobs.

I want to customize a resume for each job I apply to. The problem is:

• If I list all of the jobs for the last 10 years, half of them would not be relevant to the position I'm applying for.
• If I list only the jobs relevant to the position, the resume will show a lot of gaps of 6-12 months. (Gaps between jobs are normal, especially if you leave out "survival" jobs. But in my case they'd include substantial jobs in the other career.)
• Because there were so many short-term jobs over the last 10 years, the resume goes on well over 2 pages, even if I'm omitting the irrelevant ones.

How to handle such issues?

• Should I label the "Experience" section "Relevant Experience" instead?
• Should I have an "entry" for each gap that says something like "working in a different career"?
• Do I stop at 2 pages, regardless of the number of years it goes back?
• Anything else I can do?

Contract and freelance work isn't a "job" in the usual sense, for a resume. Instead you have the job of "freelance technical writer", for example, perhaps with an employer of MyLastName Writing Services. Now you can spend half a page on this "job" with examples of the sorts of services you provide, and if appropriate, some customer names and types.

It should be straightforward to make separate versions of this that emphasize the writing or the development, but I would encourage you to include both. A technical writer who sometimes does the thing they're writing about is usually more valuable than one who only writes.