There Are Very Complex Ways And Also There Are Easy Programs. Here is How To Save Sensor Data From Arduino To a Text File. | Arduino, Serial port, Data
How To Save Data from Arduino To A .csv File Using Processing | HACKERSCAPES
Using EEPROM in Arduino to Store Data - Iotguider
Using EEPROM to Store Data on the Arduino – Norwegian Creations
Save Serial data to a text file – Arduino, Processing, PuTTY
How to Save Arduino Serial Data in TXT, CSV and Excel File - YouTube