Managing Editor Tabs
Every time you open a file for editing, a dedicated tab is added to the editor window, next to the active editor tab.
RubyMine can limit the number of tabs opened in the editor simultaneously. When the number of tabs reaches its limit, the editor closes the tabs according to the tab closing policy, that is defined in the Editor Tabs settings page. By default, the tab limit is 10, but you can change it if necessary.
All commands, related to managing editor tabs, are available from: