Where is the data for this stored? I was inspecting and didn't see anything in Local Storage, Session Storage, nothing on the network tab. Hit refresh thought everything would be wiped, but all my data was still there!
It appears to be stored in the url. As you update the cells there's an encoded # variable that, when removed, wipes the table.
And if you put the URL into a URL shortener, you can (ab)use it as cloud storage for your spreadsheet.
I once did some checks and found at least one shortener could store a URL string of at least 65KB [1]. That was in 2009. Not sure where those shortener limits are all at today - I suspect the industry dynamics changed when Twitter introduced its built-in shortener.
1. https://softwareas.com/the-url-shortener-as-a-cloud-database...
However there is a link shortener that is quietly hosted by GitHub called https://git.io that doesn't seem to have a length limit as far as I've discovered. [1]