You can remove List Template mappings from the WorkItemCacheGlobalSettings.xml file to exclude a list type. Excluding a list type mapping from the global mapping file will prevent the list items getting added to the Work Cache. It will also remove any existing list items already in the Work Cache when a Refresh is ran.
To remove a List Template:
Highlight and remove the List Template. For example, here list type 758, the BrightWork Custom List, mappings are highlighted:
Note: Take care editing the global mapping file as syntax errors will prevent all updates to the Work Cache.