InDesign CS5 and later has an obscure keyboard/mouse maneuver that allows you to create multiple duplicates of an object as you drag. Here’s how:
1. Select one or more objects with the Selection tool
2. Hold down the option key (Mac) or alt key (Windows), and THEN grab one of the selected objects. It is very important to hold down the option/alt key BEFORE you grab any of the objects.
3. Begin dragging the object(s) horizontally or vertically, and you’ll see a duplicate of the object appear, because you’re holding down the option/alt key
4. While continuing to hold down option/alt, hit the right arrow or up arrow key on the keyboard once to create one duplicate, twice to create 2 duplicates, three times to create 3 duplicates, etc. You will see a dotted outline appear on the screen indicating that duplicates are being created.
5. When the correct number of duplicates is positioned the way you want them, release the mouse and the option/alt key
Note that this is a different technique than the more well-known technique of being able to tap the up-arrow and right-arrow keys while dragging out a frame on the page to create a grid of boxes, or while dragging out a frame with the loaded place cursor. The technique I’m describing above is useful when the object or objects you want to duplicate are already on the page, and now they need to be duplicated or stepped and repeated.