You can use the standard Windows copy and paste shortcuts if you like. The pasted entities will appear at the pisition of the mouse pointer but will likely not be on-grid.
Copy: Ctrl+C
Cut: Ctrl+X
Paste: Ctrl+V
These commands are available for selected entities in the Edit menu, and also when you right-click the 2D grid view.
Paste Special allows you more control over the duplication of entities, including adding increasing numbers to the ends of their names, so you can have them all uniquely addressable.