Exporting items for editing
You can export your items into excel/spreadsheet, make bulk or repetitive changes and then re-import to update.
Go to the Items import page
Click on the Download current items.. button, an excel spreadsheet should automatically download
Make changes in the spreadsheet, then click the Select an excel, .xls, .xlsx, .csv file to start.. button to upload your modified spreadsheet.
Map the items based on ID (key field) and they will update existing items
In order to add new items, clear the values in the SKU and ID fields, and you must also change the name of the item to something unique.