What does GRANT CONTROL on a schema do in MSSQL?
To see what CONTROL on schema brings to you, create a test user without any permission, grant CONTROL on schema to it and check what permissions he has after it:
create user test;
grant control on schema::dbo to test;

execute as user = 'test';
select *
from sys.fn_my_permissions('dbo', 'schema');
revert;

Here is what you'll get:

When you want to CREATE TABLE you should open BOL article CREATE TABLE (Transact-SQL) and scroll down to PERMISSIONS:

Now you see that even if your table is not supposed to have columns of CLR user-defined type, you still need CREATE TABLE permission to grant to your user to make him be able to create a table.
Test user has already ALTER SCHEMA implied by CONTROL on schema, but CREATE TABLE should be granted (as well as REFERENCE permission in case of CLR user-defined type).