What issues might I encounter by checking "Object Generates Menu" checkbox in the Object Designer?
Oracle Service Cloud, all versions
While creating a custom object you may notice "Object Generates Menu" checkbox.
You may select this check box to have the object generate a menu used to populate values in menus added to other custom objects. The options in the menu are populated by the values in the lookup field specified for the object that generates the menu. For example, if custom object A generates a menu, you can select the menu to populate a menu field you add to custom object B. If object A’s lookup field is set to Labels, and the object has three records created for it with labels of “One,” “Two,” and “Three,” the menu in custom object B that is populated by object A will display values of “One,” “Two,” and “Three.”
Since a menu item is added for each record created for objects that generate a menu, you will want to enable this option only for objects that will have few records created for it.
Not following this recommendation may lead into various issues in different parts of the product. As an example, you may encounter some errors during the Data Import session due to menu items that are added for each record and stored in a product's cache. With abnormal amounts of records you can easily overfill the cache which in turn can cause application crashes.
For additional information, refer to the Create a Menu-only Custom Object section in online documentation for the version your site is currently running. To access Oracle Service Cloud manuals and documentation online, refer to the Documentation for Oracle Service Cloud Products.