Adding multiple pages to the home screen and filling them with apps' shortcuts and widgets, make the home screen look cluttered. So, to add / remove home screen pages on HTC 10, do as follows:
1. Make sure you are on one of the home screen pages (Simply press the Home Button)
2. Find an empty spot on the home screen, and press and hold your finger there
3. On the opened Personalize menu, hit the Manage Home Screen Pages option
4. Now, to remove a page from home screen, simply swipe to that specific page and hit the Remove button
5. To add a new page (panel) to the home screen, swipe to the very last page and hit the + Panel button on the middle right side of the screen.