E3PROF 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 "KB Profile" 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_E3PROF TYPE E3PROF.
The E3PROF table consists of various fields, each holding specific information or linking keys about KB Profile data available in SAP. These include PROFNAME (Knowledge-base profile for SCE), OBJID (Internal counter for objects in an SCE knowledge base), UINAME (Name of external user interface for KB profile)... 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. .