Refresh Arduino Ethernet Web server + keep history on the same page

Hello, I am building an Arduino MEGA 2560 + Ethernet web server. I show the results of a temperature sensor. My question is how to update the temperature measurements + keep the previous measurements on the same webpage. So each time the Arduino sends a measurement to add the new measurements on the webpage without losing the previous...Any idea? For example I let the device all month, and captures 100.000 measurements, I need to have the 100.000 on the same webpage.

You will not have enough storage space on a Mega for 100,000 readings.

The first option that comes to mind is to store the readings in a text file on a SD card and send that to the browser when the page is refreshed.

Alternatives to the SD card are external EEPROM or FRAM modules wher you store the readings. Further the same idea.

I use microSD 32GB in Ethernet's plug. Ok, the other thing is to get all the measurements over the ethernet. What I mean is to display every time one measurement on the browser and not all of them and when the capturing method ends, to gather the measurements' file from the Arduino microSD via Ethernet/browser... How possible is that?