my question is: is there any way to move on the the next set of results (already part of the result array) without going to the controller and model again
Then my answer would be NO if you was using CGridview's pagination. In your situation, you have to make the pagination by yourself instead. You have already selected all of records, and would like to manipulate them on your client side, you really don't need the pagination of CGridview at all.
Pushing all of records into a page on first load is not good idea, but maybe your requirement has asked, I just say that.