If I have a large amount of objects in a file, is there a way to combine them to make the program run smoother?

So I'm doing this job that requires me to import a customer PDF, and when import there turns out to be around 43,000 objects in the file. For every section of this PDF with a solid color, it's not one object but rather a series of lines put close together to make the appearance of one solid colored object. What makes this worse is that I need to put about 9 of these imported PDFs into a single .cdr before I can send it back out and my computer simply can't process all of that.

Is there a way to condense all these lines and nodes into a single manageable unit? Is there some sort of software trick that might make this easier, or should I start to seek out a better computer?

Current system: 8GB RAM, Windows 7 Professional, Intel i5 3.40GHz CPU