This menu is undated, but the cover photo shows a heavyweight passenger train powered by steam, which means it is from before 1955, when the Canadian was introduced. That’s not much help by itself.
Inside, the menu offers table d’hôte dinners for $1.75 to $2.00. A 1951 menu for the Mountaineer that will be presented here in a few days has table d’hôte meals for $2.15 to $2.50, so this menu must be from before. On the other hand, a 1941 dinner menu has table d’hôte meals for $1.00 to $1.25, so this one must be from several years after that. There are no patriotic messages that we would expect to see if this menu were issued during or immediately after the war, so my guess is 1947 or 1948.