Suppose I have an animation that is 16 frames and I wanted to keep looping this over and over for 128 frames (8 times) while the camera pans around this animation. Is there any way to do this without copy and pasting the animation?
This is what the Nonlinear Animation Editor is made for.
In the Dope Sheet in Action Editor mode, select the action and click on the Push Down button:
This will remove the action from the Dope Sheet, but it's now available in the Nonlinear Animation Editor as a yellow strip:
Keep this strip selected, open the N panel of the Nonlinear Animation Editor, click on the Strip tag and under Action Clip choose the Repeat number:
To make the action come back in the Dope Sheet if you ever need to edit it, select the strip and press Tab or simply select it in the dropdown menu of the Dope Sheet: