If you are talking about the little white box that usually pops up below most text fields then that is per browser.
To delete it in Chrome you want to click the 3 dot menu > More tools > Clear browsing data. If you select "Autofill form data" here it will clear everything it has saved, so be sure you want that,
I cannot actually find a working way to inspect your autofill data in Chrome without opening the database file... It used to be possible but it seems to have been removed. There must be a way I am missing here. You can check your autofilled passwords, addresses, etc, just not your form data.
If you want to look at the database you can find it here.
https://superuser.com/questions/884029/see-all-autofill-data