When a conference has an abstracts and a later papers submission date, is okay to skip the abstract submission and just submit the paper?
No.

It's a deadline.  Follow it.

Program committees ask for abstracts early to streamline the reviewing process.  Asking them to make a special exception for you because you're not ready yet is unfair to the program committee, who would have to do extra work (however small) to accommodate your late submission, and to the hundreds of authors who got their abstracts in on time.


  The issue is that I am still working in tabulating the results from my experiments


The tabulated results of your experiments are not going to appear in your abstract anyway; only the conclusions from your experiments will.  If you don't know yet what those conclusions will be, you're not ready to submit.  So don't.  There's always another conference.

But! Remember that you are allowed to revise your abstract in the week before the paper submission deadline.  It is perfectly acceptable to submit a tentative abstract, which describes your results in enough detail to assign reviewers, and then include a more detailed/updated abstract in your paper submission.  If your conference is using EasyChair or HotCRP, you can change your abstract in the electronic submission form, and the committee will no longer see the old abstract.

If you make significant changes to your abstract in the paper submission, you risk angering the program committee members who were assigned your paper, who could (legitimately) reject your paper without review.  So don't do that.