How to transfer apps from one iPad to another

If you want to set up a new device from the backup of the old device which in effect creates a clone of your old iPad, look here for the instructions.

Transfer data from your previous iOS device to your new iPhone, iPad, or iPod touch - Apple Support

If you just want to use the same apps on one iPad as you do on another iPad, you can download your past purchases on the new iPad as long as you are using the same Apple ID on both devices. This method will not transfer you app data. You can only do that by restoring a backup.

Redownload apps, music, movies, TV shows, and books - Apple Support