using case function with insert

One more method: (This is just to show how can you use Salary in your query)

IF OBJECT_ID ('dbo.SelectQueries','U') IS NOT NULL
DROP TABLE dbo.SelectQueries
CREATE TABLE dbo.SelectQueries(Name VARCHAR (60),LastName VARCHAR (60),Email VARCHAR (60),Salary int,Employmentstart date default (sysdatetime()),
Monthduration int,Country varchar (60),Categories varchar (60));

;With cte(Name,LastName,Email,Salary,Monthduration,Country) as
(Select 'Ted','Click','tedc@robus.co.uk',50000,2,'United Kingdom')
INSERT into dbo.SelectQueries (Name,LastName,Email,Salary,Monthduration,Country,Categories)

Select *, CASE when Salary >= 35000 then 'senior Staff' ELSE 'Junior Staff' End From cte

Select * From dbo.SelectQueries

Drop Table dbo.SelectQueries