BBPUID is a standard SAP Structure so does not store data like a database table does. It can be used to define the fields of other actual tables or to process "Structure for User Data" 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_BBPUID TYPE BBPUID.
The BBPUID table consists of various fields, each holding specific information or linking keys about Structure for User Data data available in SAP. These include RCODE (Version Number Component), ACTION (Internet action ID), USERID (User ID in SAP Business-to-Business Procurement), USERTYPE (User Type in SAP Business-to-Business Procurement)... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .