And the Employee table will need the same type of fields plus it must contain the field, EmployerID so that each EmployeeName record relates to a record in the Employer table. The EmployerID field in the Employer table will be either an integer (auto-increment) or a GUID value. In a real-world situation, EmployerName would actually be broken down into separate fields such as FirstName, MiddleName and LastName.
You'll have to add the EmployerID field to the Employee table in order to link the two tables. Also, what are the definitions of Firstname & Lastname as applied to an employer? For example, I used to work for Manitoba Hydro, which would be entered under CompanyName (which is not a required field???). No one person owns that company so what gets entered for Firstname/Lastname? Only Lastname is a required field. Firstname is not. Yet in the employee table only the ID is required which is pointless because an employee must have a name. You still have some thinking to do.
I have added a new Field in the Employee table as you can see in this screenshot attached
and I'm preparing this software for the small firm not a big company,so first name and last name is required,and I have the companyname field in Employer table also.
Now how to relate the two tables?
You will also have to define EmployerID in the Employee table as a foreign key and you can define a contraint to ensure that it exists in the Employer table. How you do this depends on your DBMS. I use MS SQL but because my dev system is in for repairs I can't give you instructions on how to set this up at the moment.
You will also have to decide which fields are required and deselect the Allow NULLS option.
Both your tables have a field named ID, but in the Employee table it is the Employee ID and in the Employer table it is the Employer ID. Each record in the Employee table has to be associated with an employer. You do this by ensuring that each record contains the Employer ID.