I need to see 50 (or 100) results per page instead of 10 results per page when I am searching in the WorldCat.org database.
Is there any way to do that?
I took a look at the site for you, as well as the HTTP GET requests, and could not find an obvious way to accomplish what you desire without software augmentation.
But fret not. There are browser extensions you can use to accomplish this task.
One of the most popular is called Autopager. It will work with most popular browsers.