I think Harald and James covered the bases here, but a couple of comments on Harald's reply:

(1) Definitely check this. A common cause of indexed https: pages is that a secure section of your site is being crawled (like a shopping cart), and you're using relative navigation links (like ) - when a crawler or visitor hits the nav link from a secure page, the relative link grabs the https: In most cases, you may want to NOINDEX secure pages. Shopping carts and checkout pages have no business in the search index, IMO.

[(2)-(5) I believe this does work, but it's very tricky, so please be careful. If anyone has linked to the https: pages, you'll lose the link-juice this way (you'll just cut those pages off). I honestly don't think it's a good choice for most sites.

(8) I actually believe the 301-redirect is simpler in most cases.

As James said, sitewide canonical tags (or on the affect pages, if they're isolated) will also work.](/contact.php)

I doubt it would harm you, but it is a bit unorthodox. Why not make the table header a header tag?

I'd argue with the "take up space unnecessarily" point a little. Headers aren't just for SEO (their SEO impact is probably pretty small these days) - they're for visitors. If these pages get direct visits (including from search), a prominent header can really help people know their on the right path. Breadcrumbs are great for people who are already on your site and have a sense of it, but they're too small and complex for that 5-second test of "Am I in the right place?"