each memory card only has 15 blocks. that is the limitation of the PSX. however, you may have as many memory cards as you want (well, as much as your hard drive has space).
you can manage your memorycards, either PSXmemtool or PSXeven's built in managers will do it for you.
you can manage your memorycards, either PSXmemtool or PSXeven's built in managers will do it for you.