COOBJ_PERI 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 "Master objects with periods for which they are valid" 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_COOBJ_PERI TYPE COOBJ_PERI.
The COOBJ_PERI table consists of various fields, each holding specific information or linking keys about Master objects with periods for which they are valid data available in SAP. These include BUPER (Posting period)... 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. .