Suggestion
ObjectARX and .NET applications
While there is no enforced limit on the number of elements in Context menus, other applications may add entries as well, so try to limit your entries to less than six per menu, unless the menu is for commands or objects that your application defines. Beyond that, build a menu tree structure for less-commonly used options. Also, never remove menu items added by other applications unless you have an agreement with that application's author to do so.