Hi makumbisulaim...,
Use CONCAT function for contenating Subject and Teacher column.
Then update the the value in the first table.
SELECT CONCAT(Subject, '-' ,TeacherName) AS 'Schedule' FROM TableB
Example:
Database
For this example I have used of Northwind database that you can download using the link given below.
Download Northwind Database
Query
SELECT CONCAT(FirstName, ' ' ,LastName) AS 'Name', City, Country
FROM Employees
Screenshot