MASS PASTE

I know there's some option in 2K, maybe 2K3 called "Multi-Paste". Never used it myself, so I have no clue how it works, nor do I remember the context where it can be used. If you're in XP/VX, I don't think there's any such option. Not that I can recall. I'm sure I must have attempted the "Shift" method of multi-selection, but that doesn't work in the context of the database in any maker.

Yes, but Multi-Copy works differently. It copies a lot of monster groups together, it does not duplicate one monster group many time.

In your case, I'd just copy the first monster group and then just repeatedly hit the arrow-down key and Ctrl+V.

I know it's not a huge improvement or anything but you could always ctrl+A to select all the information in a battle event page and then ctrl+V to paste it. Also there's event page copying and pasting rather than copying monster groups and having to change the contents of them. Other than those I'm not sure if there's much you can do, sorry.