Re: My husbands contacts are appearing on my iPad
Are you using the same Apple ID? And where is the email syncing from, ie, is it Gmail confined to the Gmail app, the Apple ID email, or some other email address and/or app? If it is due to the Apple ID, sadly Apple has designed that system to generally be a 1 person thing, hence the addition of family sharing, etc in the last few years, so that family members can share music, apps, etc, while keeping your core Apple ID individual.
If it is more of an annoyance issue with email that you don't want to read that mail and have it appearing on your iPad, you should be able to go into Settings, then select Mail, Contacts, Calendars, then you should be able to select the account that is syncing with the iPad and disable mail, contacts, etc.