The app drawer layout on HTC 10 can be changed in order to see more/less apps in every page. Available options to change grid size on HTC 10 are 3x4 and 4x5 and you can do as follows to specify the number of apps in each row and column:
1. Open the App Drawer on your HTC 10
2. Hi the 3-dot icon on the top right of the screen, followed by the Grid Size option
3. Now select between 3 x 4 layout or 4 x 5 layout
Note that, this change doesn't affect the home screen's layout.