To add new tables, or columns:

1.  Open an existing database by clicking the Open Database button

2.  Add the table or columns you would like

3.  Click the Sync button

 

Easy Database Creator does not support changing column names, types, lengths or nullable.

 

Why is the Sync button greyed out after I have opened a project? 

Use the Open Database button, not the Open Project button.  Projects are used for Creating Databases, not for working with existing databases.