Nothing. It wasn't and will never? be designed to do that as long as we're talking about selecting a range of table rows in one or more table fields. Access is a relational db, not a spreadsheet tool. The closest you can come to the desired behaviour is to Paste>Append from the ribbon. This will fail if the operation duplicates records in an indexed field or creates records on the many side of a one to many relationship.
We're talking about pasting into new rows in a table, not existing ones? For existing, I don't know.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.