If you need support from Yola please contact us via firstname.lastname@example.org or make use of our live chat service! We are working on a new approach to community-based support and during this transition period we are not adding any new threads to this forum. Many thanks to everyone who has participated over the years and we look forward to unveiling a new peer-to-peer support system soon!
I'm afraid that there's curently no option to hide particular pages from the view in Page Manager. It'll always display all your pages and a scrollbar to navigate up and down. Page Manager was designed for offering an easy drag-and-drop option to arrange pages, and I admit that it may get tricky to manage a high amount of pages from there.
So I won't be able to offer you a quicker solution for managing your pages with the Page Manager. I'm sorry I don't have better news for you at this stage.