SQL Security?

T-SQL or what kind of permission needed to the login to create there own table, drop there own table, update/insert data to there table and delete data from there own table.

Allow user to do anything within his own schema

GRANT ALTER ON SCHEMA::dbo TO MyUser

Would give them permissions to create, alter or drop objects in the dbo schema.

GRANT INSERT, UPDATE, DELETE, SELECT ON SCHEMA::dbo TO MyUser

Would allow MyUser to view, insert, update or delete data in the dbo schema.
These permissions are granted to database users, the only permission granted to a login at the database level is connect. All database object permissions are granted to users.