Not quite - the BA lounge complex at YYZ is divided into two entirely separate areas: the "First" section on the right hand side of the reception area and the (much larger) "Club" section on the left hand side of the reception area. As pointed out above, there are separate dining facilities within each section that you will only be able to access with the pre-flight dining voucher (First or Club World, depending only on your class of travel) issued to you upon your arrival in the lounge. If you are flying in Club World but entitled to use the "First" section of the lounge (i.e., because you are BAEC Gold or OW Emerald), you can simply wander over to the "Club" section and enjoy the pre-flight dining buffet there (or indeed take your food back into the "First" section if you prefer). Incidentally, the staff in both sections are - at least in my experience - rather impressive (proactive, friendly, approachable, etc.), so you will probably enjoy your time in the lounge.