Just a little update and info:
I've contacted the client service of pocketbook they has answer me that their e-reader its capable to read the .epub format up to ~50Mo (maybe more) and for test i try to merge many book with calibre to make an epub who weight 25Mo and my inkpad3 open it quit faste for a book of this size without any issue, i try 50Mo but calibre make too much time to merg that and finally crash.
So maybe my e-book (l'épée de vérité l'intégrale 12Mo) have an issue that dont disturbe the tolino vision 4 hd.
