While Jaskaranbir's answer should work if you've setup device manager to do that (AFAIR it requires you gave it the corresponding permissions on your device), there are other means you can use in case you have not. Order of tasks might be important here, since as soon as your device "lost contact" to its Google account, you can no longer address it remotely:
- Login to your Google account using your web browser
- locate Plan B, and hit the Install button. Select your device from the popup, which pushes the app to it.
Now you should be able to access the device via the corresponding web interface of the app developer. Another app working in a similar way is Android Lost. You can find additional details in our lost-phone tag-wiki.
You can still try ADM after having pushed one of these apps. Just make sure to not lock out (i.e. "de-authorize" it via device manager) the tablet before you've reset it; once de-authorized, you can no longer access it ;)