Do all hams require refrigeration?

No. Some varieties, such as canned hams and dry-cured ham, are shelf stable and may be stored at room temperature.
However, most hams should be stored at a temperature of 40°F to retard bacterial growth. The amount of time ham can be refrigerated depends on the type. In general, fresh and cured ham can be stored in a refrigerator for several days.
 
When purchasing ham, be sure to carefully check the label to see if it requires refrigeration.
 
Source(s):
RecipeTips.com "Ham Handling, Safety & Storage"