API to read multiple SBDF files consecutively and append them as a single data table

I'm proposing an API to read multiple SBDF files consecutively and append them as a single data table.

If CustomDataSource is fetching a large SBDF file from a file server (e.g. samba server), I think it would be faster to split it into several SBDF files (kind of chunks) and transfer them in parallel rather than transfer as one SBDF file.

And to implement this, I'd like an API that appends multiple incoming SBDF files to a document as a single data table.

* The idea of the proposed API is to quickly add a large file(tens of GB) from a file server from a CustomDataSource, so it's okay if other methods are implemented to improve performance.