How to Customize the Windows 8 Start Screen
To add more tiles to your newly created group, drag and drop additional tiles into the group.
Drag and drop new tiles next to your new group’s first tile. After you drop a tile into a group, you can drag the tile around to a new position within the group.
Want to create yet another group? Then repeat Steps 4 and 5, dragging and dropping a tile between two more groups to create yet another group.
You might find groups of related tiles to be enough organization for you. If so, stop. But if you want to label the groups or move the groups to different positions on the Start screen, go to the next step.