Is there a tool for mass uploading document records and its associated attachments?

Yes, you can use the HCM Data Loader (HDL) tool to do so. For details about loading document records using HDL, refer to the Oracle Human Capital Management Cloud Integrating with HCM guide on Oracle Help Center.

Additionally, there is REST API support for document records. Therefore, users can build a simple extension to programmatically load document records using APIs. For details about REST services for document records, refer to the REST API for Oracle HCM Cloud guide on Oracle Help Center.