If a table is made with the wrong primary key the whole table needs to be built again. With small tables this is no issue but with large tables this can be time consuming.
When editing a table it should be possible, providing the table has no data and is not being used in a calculation or import, to change the Primary key. To do this the system could generate a DELETE TABLE and CREATE TABLE script in the background. When we change the tables key the CREATE TABLE script is updated and when we press save the old table is deleted and the new table is created.