It's an odd looking set-up but I think it looks as if first Cass family just don't have their head of household at home that night. Joseph Cass in the first lot can't possibly be the son of Thomas in the second lot because Thomas is only 14 years older than he is, and if he was Sarah's son he would have a different surname unless her first husband had been Mr Cass as well! I can't find a suitable head of household anywhere else in Ware though. I have seen that before though, when the head of household just isn't there, usually when he's away in the navy or something
No idea why the enumerator put little Florence Campkin on the next page rather than the empty line on page 9, maybe he just made a mistake. She must belong with your family. Maybe the Cass's will just have to remain a mystery!
Cheers Veron