You can rearrange and change toolbar buttons, menus, and menu commands by using the mouse or you can use the Rearrange Commands dialog box, which you can access by using the keyboard. Tasks that you can accomplish by using the keyboard are identified as (keyboard accessible).
You can add a separator bar before the first and after the last item in a group to distinguish the group from other buttons and menus (menu: A list of commands that is displayed when you click a menu name on a menu bar or other toolbar.) on a toolbar.
Group related buttons and menus on a toolbar
Note To remove a separator bar between two buttons, drag one button closer to the other.
Group related buttons and menus on a toolbar (keyboard accessible)
Note To remove a separator bar from a toolbar, click Separator in the Controls list, and then click Delete.