Object data is attribute data that is attached to individual objects and stored in tables in the drawing. Object data tables store text and numerical information related to an object.
To use object data, first define the format for the table, and then create each record as you attach it to an object.
After you define an object data table, you can associate it with one or more drawing objects. When you attach object data to a drawing object, AutoCAD Map 3D toolset creates a new record in the selected table and attaches the record to the object. You can create more than one record for each object, and you can attach records from more than one table to an object.