The sentence "If I were you, I would take up the job." is an example of a second conditional sentence.
Structure of second conditional:
In this sentence:
"If I were you" is the hypothetical condition (using "were" instead of "was" is correct in formal English for all subjects in hypothetical situations).
"I would take up the job" is the result or action that would happen if the condition were true.
The second conditional is used to talk about hypothetical or unreal situations and their possible outcomes.