I'm not sure there is a tab per se Serious_Developer. But you can mimic a tab by using a string literal;
------------
SELECT last_name
|| ' '
|| job_id AS "Employees"
FROM employees
-----------
There's 11 spaces in the string literal.
1 space to appear after last_name
9 spaces that you want
1 extra space (to appear before job_id is displayed)