There is an AC departure lounge at YYZ which is quite nice that you'll have access to if you're in J going to TLV (sounds like you are).

However, if you've got a full 8 hours or so, and there are no extra security procedures for flying to TLV (at least on AC) than any other international destination, then you should have plenty of time to check out downtown Toronto. You'll have to clear Canadian customs though.

I'm pretty sure there are a bunch of other threads in this forum about what to do/see with X hours in Toronto.