Click "Calendar" from the left navigation pane to go to Outlook Calendar view.
By default, the Calendars in the "My Calendars" group are displayed, if not, click the down arrow proceeding "My Calendars" to expand the list.
Right click "Calendar" under "My Calendars" and select "New Calendar..." from the pop-up menu.
The "Create New Folder dialog box pops up, name your new calendar (in this example, I named it "Test" and then click "OK".
The new calendar is displayed under "My Calendar" group. Click its name to open the calendar. By default, it opens side by side with your main calendar. You can click the left pointing arrow to overlap them.
If you want them to display side by side again, you can click the right pointing arrow to separate the two calendars.
To delete a calendar, right click on its name and select "Delete Calendar" from the pop up menu. You can also move the calendar to a different group by selecting "Move Calendar".