Thanks for the helpful replies. I have friends in Toronto who could pick up and drop. Rationale for dinner outside is effectively be able to meet with them as well - rather than trying to kill time @ airport. Question was more, can I leave the airport (i.e. Clear immigration in YYZ and then re-clear security to go back into the airport) or was that a big no when going US->YYZ->Int'l. Sounds like I can go out of airport if I wish in the 5 hours I have to kill.

Please advise if not the case. Thanks for all the helpful responses!