E1EPC02 is an SAP Structure so does not store data like a database table does but can be used to process "Handling Unit Header EPC Segment" Information within sap ABAP programs. This is done by declaring abap internal tables, work areas or database tables based on this Structure. These can then be used to store and process the required data appropriately.
i.e. DATA: wa_E1EPC02 TYPE E1EPC02 .
Below is the documentation avaialable and full details of the fields which make up this Structure.
|Data Type||length (Decimals)||Check table||Description||Conversion Routine|