The cook & serve part – notably the cook – is the key to your question. If it says "cook," we would cook it.
Mass-market hams in this country are cured, they may be smoked (often lightly), and they are cooked, partially cooked, or not cooked before being sent out to stores. The hams that are cooked have been cooked to an internal temperature of at least 148°F (65°C). They can be eaten cold, at room temperature, or warmed. Partially cooked hams are heated to an internal temperature of 137°F (58.5°C), which is hot enough to kill any trichina parasite, but not to kill all bacteria.
So partially cooked and uncooked hams need to be cooked through to ensure safety. How long you cook it depends on the size of the ham. An uncooked or partially cooked bone-in ham weighing 10 to 14 pounds should cook at 325°F (160°C) for 18 to 20 minutes per pound. You will want to check it with an instant-read thermometer to be sure you have reached the right temperature (as with any large meat, the temperature will continue to rise after it leaves the oven, so we would think about withdrawing it shortly after it hits 150°F (60°C).
Most producers and – down the supply chain – a fair number of supermarkets are very good about providing cooking instructions for hams and other meats. We are not shy about asking the butchers and meat cutters at our nearby grocery about cuts and preparation recommendations, and they generally know what they are talking about.
The U.S. Department of Agriculture says, "Hams that must be cooked will bear cooking instructions and safe-handling instructions. Hams that are not ready to eat, but have the appearance of ready-to-eat products, will bear a prominent statement on the principal display panel indicating the product needs cooking, e.g., 'cook thoroughly.' In addition, the label must bear cooking directions."
We realize that you are in Canada, so all this USDA stuff probably sounds like gibberish, but we thought your government was at least as paternalistic as ours.