Yes, you can place a stack of documents to be scanned on top. For me, however, it often feeds the paper a little unevenly. If I want a really good scan, I let the documents through one by one. Perhaps this could be set better or I'm doing something wrong.

do you mean the top feed, yes it is automatic.

HO OfficeJet 9730e does not have AFD.

Yes, but the ADF is only up to A4. A3 is only possible on the scan glass.
However, the ADF can scan both sides of double-sided A4 sheets at once without having to turn the sheet, as it has a reader at the top and bottom