To see the changes log of your table scroll down to the issue Activity panel and select the Table History tab. Use the arrow in the top right corner to sort the history in ascending or descending order.
Formula column in Table History
Enabling an option to make formula-calculated values searchable via JQL also brings changes to the Table History tab.
Once the option is enabled, and a re-index is performed, that saves all the pre-existing issues into a database. As a result, those saved values from the formula column are displayed separately one time in the Table History tab.
If any changes are made in the Formula column after re-index, those will be displayed as a change within the whole table.
Example:
A re-index has been performed, and the values from the Formula column have been saved and displayed separately (see table update for rows 860, 873).
A user has manually updated the table, particularly the Formula column. Table changes are displayed as usual.
All values are stored exclusively in Jira’s database.