MapInfo Pro stores information about spatial tables and views in the database. It stores this information in a file called MAPINFO.MAPINFO_MAPCATALOG (the Map Catalog) as a special table on the DBMS you are accessing.
The MAPINFO_MAPCATALOG is a registry table for databases that stores metadata about spatial tables and views in the database. Using the tablename and ownername as the key, the MAPINFO_MAPCATALOG identifies the spatial type, spatial columns (if there is more than one), projection, data bounds, and rendition information. The MAPINFO_MAPCATALOG is used by a number of MapInfo products, including MapInfo Pro, that access map data from databases.
There must be one catalog per database, which is required before mapping any tables on that database in MapInfo Pro.