MySQL Cluster does not currently feature auto-discovery of databases on SQL nodes, so you have to manually create each database on each SQL node before MySQL Cluster will start to show the tables. You can create the database on some SQL nodes after you have actually created the database on another SQL node and created the table; you can consider using the create database command as a way of saying "go look for my cluster tables in this database." You should also run FLUSH TABLES after you have completed the database to make sure the SQL node picks up the tables. You do not need to create tables on each SQL node. MySQL features auto-discovery of tables, so you simply need to create each database on each SQL node.
If you drop a database, you will delete the tables within it from all the storage nodes. So be careful; you can't just drop the database and expect it to remain on other nodes!