This feature is a bit hidden and unintuitive within the AEM Ensemble interface. You have to view your site in Column View in order for the Copy command to appear in the menu above the file list. The copy command does allow you to copy multiple pages at a time, unlike the Move command used to move and rename pages. It will also copy recursively, meaning that any sub-pages under the page(s) being copied will also be copied.

Copy Page Image 01
Switch to column view by clicking on the "List Layout" button in the top-right corner of the AEM Ensemble interface above the page list, highlighted in the image above (click for larger view)
Copy Page Image 02
Once in Column View you will see the "Copy" button appear along the top tool bar (highlighted in the image above). Select the page or pages you wish to copy and click the Copy button. Note that the Copy action will copy subpages, and you can select multiple pages to copy at a time and it will copy any subpages.
Copy Page Image 03
Once you've clicked the Copy button the tool bar at the top will change and the Paste button will appear (highlighted in the image above).
Copy Page Image 04
Select a destination for the copied page(s) and click the Paste button.
Copy Page Image 05
Depending on how many pages were copied the busy spinner may appear. The copied page(s) should now appear in the destination location.
Copy Page Image 06
If you had subpages, those should also be there.