I guess you are using the iPad's email client and not Outlook? Alima's suggestion should work. You may even be able to access your email provider's website via your iPad to delete the mails but you may find that you don't have access to all the tools/functions available on the website.
The other possibility is that you are using the iPad's email client and have switched on the backup to iCloud. If you open iPad's settings, open the iCloud settings as well and check whether you have toggled the Mail button to 'On'. If you have, turn it off. It may take several goes to delete them all but they shouldn't keep coming back.
There are a couple of other things you could try but you would need to provide a bit more information. Let GN know via this forum how you get on.
Last weekend, in Rutland, the first statue in Britain of the late Elizabeth II was unveiled.