hi My devt envt is Arcgis server 10.1 / arcgis silverlight API. Am using feature class in which one-many relationship is built with table. Is it possible to edit the related table data using out-of-box funationality for web application
Since you mentioned you are working with the ArcGIS API for Silverlight, it is possible to enable this functionality with some API development. Some resources: Query related records Silverlight API - Dev sample