They remain edible for months and even years, but they will eventually start tasting like the freezer.
When kept in a cool dark place, canned foods remain edible for years.
Pasta, rice, lentils will keep for years. Snack bars, crackers and cookies may perhaps lose some of their freshness and their “crunch”, but are certainly still edible after a few months. Chocolate keeps for 1 year after the date and honey forever.
The vinegar contained in most condiments preserves them for a long time: Ketchup, mustard, sauces and vinaigrette are usually good for months after their expiry date. Mayonnaise a little less so, because of the eggs it contains.