the file manipulation behaviors are the same as the DFP behaviors.
the uploaded files will be stored on the server, you should be storing the uploaded file name in the database.
"Do I need to create another table and link it to tblcases by CaseID to store all documents?"
yes, if you are creating a one to many relationship (one case to many documents) the file names should be stored in a separate table.
send a copy of the insert page so i can examine the full page code to determine why the upload is failing.