A ham is a severed thigh of pork, usually cured to prevent spoilage. It’s a period foodstuff – the illustration is taken from a book of hours from Poitiers, c.1475, now in the Pierpont Morgan Library – but no period examples of its use in heraldry have been found. The Society’s default for the ham is fesswise, with the narrow end (the “handle”) to sinister. See also leg.
Morgan of Osprey bears as a badge: A ham reversed sable boned argent enflamed on the upper edge proper.