Multiple keywords can be imported using the the Import button under the text fields in the list edit and create view.
Once you have clicked Import you will see a textarea where you can paste your keywords with one per line. These can be copied from Excel, Word or similar.
After pasting or writing your keywords you can click on "Import Keywords". If you have any errors they will be shown and you would see on what row the bad keyword is. All duplicates and empty rows will be removed automatically on import.
Once imported the modal will be closed and you can see the keywords imported. To save your words added to the list click "Save Changes"
The keywords you have imported are now live.