La fonction de suggestion automatique permet d'affiner rapidement votre recherche en suggérant des correspondances possibles au fur et à mesure de la frappe.
You do have the ability to delete any records that you just created and then reimport them using a CSV file with a value for "Contact Owner" for each record, or you can simply update the "Contact Owner" value for the contacts currently within the system. This is the best option if there aren't a bunch of unique owners or you can use another value to filter contacts by owner.
If that's too much of a lift, you can definitely edit your spreadsheet accordingly and reimport the record. As long as all contacts have an email address, they should update with any new info (so I don't believe you would need to delete the contacts and then re-add them, unless you really wanted to).