The Data Dictionary library (TBDICLB) is intended to contain a corporate data dictionary, if you use a dictionary. tablesONLINE/CICS can be configured so that the Views you create, as well as all tables containing corporate edit rules or codes, are stored in this library.
The Data Dictionary library initially contains only the TBOLM2M table. This table is used to assign Table Object names to View/Table combinations. This facility is described in detail in the tablesONLINE/CICS User’s Guide.