Audiovisual data storage is enhanced using an expanded physical object table utilizing an ordered list of unique identifiers for a particular object for every object instance of an object contained in segments of a data file. Two object instances of the same object in the same segment have different object identifiers. Therefore, different instances of the same object use different identification and the different object instances may be differentiated from one another for access, editing and transmission. The necessary memory required for randomly accessing data contained in files using the expanded physical object table may be reduced by distributing necessary information within a header of a file to simplify the structure of the physical object table. In this way, a given object may be randomly accessed by means of an improved physical object table/segment object table mechanism.