[Scale-N]

Long press one of the songs from the big PDF and select "Copy Song" from the menu. The song editor opens where you can edit the meta data. On the "Files" tab enter the according page in "Page Order". Repeat that for all songs from the PDF that you want to use. Proceding like this you create many songs with their specific title and meta data. All of them reference the same file, no need to worry about wasting memory.
You can check that easily: delete one of the songs and check "Delete Song Pdf/Image/Text Files". The  other songs will also lose their file.

Hello !

Thank you for this explanation.
It helps me to manage my song coming from 6 differents Jazz (new) Real Book.

Do you know a more conveniant way to procede ?
It would be easier to navigate in a big pdf file, selecting the songs with bookmarks, and  then converting the bookmarks into a new song. The created new song would be the same as the copy as created in your method descibed above.

Or, does it exist a method with the Companion tool ?

 Or why not with a CSV file containing the pdf file source, for instance using:
"song1 ; page 25 ; RealBook2.pdf"