I’m assuming you have both columns has same (attachment) field type?

When I copy individual attachments it works


But if try to copy, say 10-20 columns worth, it doesn’t work

Like mentioned before, you have to copy into the same Field type.

You also have to make sure you’re using the same Airtable app or website. I.e. if you’re copying from an Airtable website view, and pasting into an Airtable app - it won’t work.