A few friends have been moving to tablets and I get asked questions about hard resets when they jam them here's one video Lenovo have put out about how to hard reset selected tablets:
Android System Recovery - Hard Reset - S2110, A2109 - Lenovo IdeaTab (Tablet)
More support videos on: Tablet (IdeaTab / IdeaPad) Support Videos Index Page
In case your IdeaTab has a problem and you are not able to see the home screen when you turn it on, you will still have a way to reset the tablet to make it work again.
This video shows how to make System Recovery - Hard Reset on Lenovo IdeaTab (Tablet) S2110A, A2109A:
Battery must be fully charged
All your data will be deleted
S2110: press "volume down" + "power"
A2109: press "volume up" + "power"
Use "volume" buttons to navigate
Use "power" button to select
Press "volume down" button,
Until "Yes -- delete all user data"
Press "power" button to confirm
Press "power" button to reboot
Wait until the process is complete