Unfortunately, you can't remove those names from your e-mail. It's one of the "features" provided by Apple. It has been a constant complaint from iPad users (maybe even all iDevice users) since they first appeared. There is no way to clean that "helpful" part out.
The only consolation I can give you is the knowledge that you are not alone. Oh, and eventually, if you use enough emails, that name should sink down the auto-list where you might not see it.
The other you could do is submit a customer report to Apple and ask them to fix this feature. Hey, it could work!
Sorry to be the bearer of bad news.
Marilyn