When you Select source tables for distribution, if Connect CDC Director finds a table with the same name on the target server as the table you selected on the source, the table mapping is built and the EDMM changes as described below. Table names that are spelled the same but have different capitalization, owners, or catalogs qualify as the same.
The available table you chose on the source server is moved from the Available Tables branch to the Sending Tables branch.
The target table is shown under the Target Tables sub-branch of the Sending Tables branch.
The target table mapping is shown under the Receiving Tables heading on the target server.
Sending table columns are mapped by default to target table columns that have matching names (capitalization excluded).