Please read Nano-10 User's Manual Page 1-8 regarding using the 1024 words of pseudo EEPROM.
Briefly speaking, you would use the SAVE_EEP and LOAD_EEP as if they are EEPROM. But the data saved with SAVE_EEP are written into temporary static RAM location and will not be saved into non-volatile memory until you run the SETSYSTEM 252, 0 function which update all 1024 words to flash memory in a single action.