Q: I was looking for help in deleting an incorrect mail contact entry.

Open Contacts, choose the contact, Edit, and then  at the bottom of the page, Delete Contact.  Reboot the iPad by holding both the power and home buttons until the apple logo appears, ignore the red slider if that appers.  Open Contacts and tap the + to add a new contact and enter all of the information you want.

Ralph has it right.  Except you do not need to reboot after editing a contact, unless something goes wrong or gets hung up.   simply find the contact in contacts, press edit - fax fix your error.

In theory you do not need to reboot...but I have made that part of my process to be certain all remnants re removed from volatile memory.  Just my approach to good housekeeping.

Ralph

You sir, are cleaner than I am!

A little paranoia is not a bad thing, sometimes these systems ARE out to get you :-)