How to transfer contacts from iMac †o ipad using Big Sur OS

Should be able to connect your iPad to the Mac and use the macOS Finder to sync stuff from your Mac to your iPad.

Another way, if you have a wireless, Home network is to use AirDrop on both the Mac and iPad to Airdrop the contact files from your Mac to your iPad.

Sync contacts and calendars between your Mac and iPhone or iPad - Apple Support

https://appleinsider.com/articles/21/01/19/how-to-turn-on-airdrop

Best of Luck to You!

AirDrop moves data one at a time or in groups of files/data. It will NOT actually merge any data/contacts.

So, you need to AirDrop contacts that you do not have on your iOS devices OR AirDrop ALl of your contacts to your iOS devices and delete manually any duplicate info/contacts.

If using iOS/iPadOS 14 AirDrop is activated in Control Centre by long pressing on any of the wirless connection button options.

Long pressing any one of these brings up all of the device connection options in a larger pop-up screen.

Best of Luck to You!

Did you try using the AirDrop method?

Well,

At least that worked!