Out of the box, the S10 arranges home screen and app drawer icons in 4-by-5 grids, but you can up this to 4-by-6, 5-by-5, or 5-by-6 if you don't mind sacrificing a bit of icon size along the way. Long press on a blank part of the home screen, then choose Home screen settings. Both the Home screen grid and Apps screen grid choices given you options and you can take your pick. You'll see a preview of the change first, and you can tap Apply to confirm it.
