Fixed means doesn't depend on PPAGE :smileyhappy:. This applies to flash only. There are two fixed flash regions in 64k memory map: 4000h-7fffh and c000h-ffffh.
Unpaged memory space means memory space directly accessible without any manipulations to paging registers.
EEPROM, RAM and registers memory block are not paged. If you remap any of these blocks with INITx registers so that they overlap, then EEPROM has priority over flash, RAM over EEPROM and flash, and registers block has highest priority. When memory blocks overlap, then only the highest priority memory block is visible to CPU.