I have always understood that you cannot contract HIV from an object that has been exposed to air, (everyday conditions not in a lab).
For instance, I pick up a knife from a table that someone else with HIV had in their hand. They had accidentally cut themselves and were slightly bleeding, (a little blood on the knife). I have a previous cut on my hand also, it is not bleeding but not completely scabbed over either. Is the consensus still that there is virtually no possiblility of getting it this way, or has any cases been documented with it passing this way?

Even for this instance, the risk of transmission is very low. It would increase if for example...the HIV+ person had a cut, a considerable amount of blood is left on the knife, and it is still fresh (a few minutes), then you cut yourself with the same knife and bleed significantly. Ovbiously by what you describe, this does not apply to your particular case.

There have been a few cases of HIV transmission by exchanging blood in accidents, such as bumping of heads and bleeding during sports, or exchanging blood during car accidents. But this is non-significant compared to the actual means of transmission, such as unprotected sex and sharing of infected drug needles.