How to transfer .cr3 files to the ipad?

There is no camera raw on the iPad, but Lightroom CC for the iPad probably needs an update before it can read these rather new raw files.

Lightroom CC does not directly read raw files from the memory card. You have to transfer them to your Camera Roll first, and then Lightroom can import them from there. If you connect the memory card to the iPad and you do not see the CR3 files, then that means that Apple needs to add support for these files in iOS, not that Lightroom needs an update.