In short, boris gave a great description on how to fix the problem:

"To change the name displayed in the Library, tap-and-hold the PDF item and select "Info", then "Edit". You can now edit the "Title" and "Author" that the Library displays. "

and szegan gave some info about a tool to do it on your PC:
"Here is another tool to edit the metadata in PDFs before you upload them to the eDGe's library:
BeCyPDFMetaEdit http://www.becyhome.de/becypdfmetaed...iption_eng.htm
It seems to be more handy for this purpose than the jPDFTweak tool mentioned before."