ROXPPD0008 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 "Operational item persisted 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_ROXPPD0008 TYPE ROXPPD0008.
The ROXPPD0008 table consists of various fields, each holding specific information or linking keys about Operational item persisted data data available in SAP. These include GUID (Guid for application objects), EXTERNAL_ID (Project Planning: External Indentifier of an Element), PORTFOLIO_GUID (Guid for application objects), PARENT_GUID (Guid for application objects)... 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. .