Is it permissible to take a work laptop, without the company's knowledge, as part of the delayed salaries owed to me, knowing that the value of the device is much less than the value of the salaries?

It is not permissible for a company to procrastinate in paying an employee his due or to delay it without right, for the Prophet, peace and blessings be upon him, said: "Give the laborer his wage before his sweat dries." And Allah Almighty said: "There are three whose adversary I shall be on the Day of Resurrection: a man who gave a promise in My Name then broke it; a man who sold a free person and consumed his price; and a man who hired a laborer, benefited from him, and did not give him his wage."

If the employee can obtain his right through legitimate means, he is not permitted to take the device entrusted to him, for Allah Almighty says: "Indeed, Allah commands you to render trusts to whom they are due," and for the Prophet, peace and blessings be upon him, saying: "Return the trust to the one who entrusted it to you, and do not betray the one who betrayed you."

As for the oppressed taking from the property of his oppressor an amount equivalent to his right without the oppressor's knowledge, there is a difference of opinion among scholars regarding this, and it is known as the issue of al-Zafar (taking one's right by force).