Your table will be updated with the following changes to match the database. (Visual Database Tools)
The Table Designer needs to load information about the table to which you are trying to create a relationship. For example, it needs to load the details about the other table's columns, so you can choose which columns from the table you are designing correspond to columns in the other table.
The contents of the database and the in-memory contents of the Table Designer are in conflict. This conflict occurs because another user has recently modified the table you are working on, but the Table Designer retains the older version of the table in your local memory.
The body of the message shows the details of the conflict. Before proceeding to load the other table into your local memory, the Table Designer will reconcile these conflicts accordingly.
Note
The Table Designer does not reconcile all differences between your local memory and the database. It reconciles only those differences that would otherwise prevent you from creating the relationship you are trying to create.
See Also
Concepts
Error Messages in Visual Database Tools