A form control that allows for the management of a many-to-many relationship with custom table data, persisted via a join table.
The Many-to-Many Relationship Manager form control allows specifying multiple associations with custom table items. It is similar in functionality to the built-in "Multiple choice" form control, but it persists the relationships in a third join table. The normalized data organization supported by this control has several benefits including better data integrity and more efficient querying.
More info here: https://github.com/adaptdev/KenticoContrib/wiki/Many-to-Many-Relationship-Manager