Yes. If you like, you can use the Upload Items feature to upload many items at once. The Upload Items feature also allows you to make revisions to your existing items.

To add items to your catalog in bulk:

1. Sign in to your Yahoo! Store account.
2. Click the "Catalog Manager" link in the "Edit" section of your Store Manager page.
3. Click the "Upload Items" link.
4. Click [Download] to download a spreadsheet containing your existing item information.
5. Select the table to which you would like to add your new items.
6. Choose ".csv" as the separator type.
7. Add your new items to the spreadsheet. Feel free to make whatever revisions you like to your existing items.
8. Return to the Upload Items page.
9. Click [Upload] to upload your items spreadsheet.
10. Once you have uploaded your spreadsheet, click [Add] to append your changes to your existing table or [Rebuild] to overwrite your existing table.

Note: When the [Revert] button is active on the Upload Items page, you can revert to the last saved version of your catalog.