Every table formatting action with UpSlide relies on the same principle: successive clicks on a single button will cycle through all available formats before re-applying the initial format.
This means that any formatting action on a table can be undone by clicking again on the button responsible for the unwanted formatting.
Update (starting V4.0): You can now undo formatting actions with Ctrl+Z!
UpSlide formatting actions are now integrated with Excel native undo system.
We are now working on the following limitations:
1) Each time an UpSlide action is performed, the undo stack is cleared. This means that you can only go back a single UpSlide action (but as many standard actions as before).
2) The undo system does not yet include the smart format of charts.