To easily add multiple localized labels or messages at once, an export and import tool are available from Admin --> Settings --> Language & Region Settings.

Under Bulk Translation, choose the language needed for translation and click Export. Note that this tool allows updating of one language at a time. In the downloaded CSV file, users can view all the labels available for translations and any existing translations for the selected language. Users can update existing translations or enter new translations for new values in the Translated Label column.

Related Documentation:

Vault Help Documentation: How to Use Bulk Translation