No. An executor must carry out the wishes of the deceased precisely as directed in the will. The executor owes the beneficiaries a fiduciary duty to carry out the terms of the will and to ensure they receive their gifts. A beneficiary can sue the executor if they do not do this.
The deceased may specifically state in the will that the
executor is to be paid for the work of administering the estate. Even if the will makes no such provision, the executor may apply to the court for a commission for the work performed however they can't just take what they think is fit. The executor has to satisfy the Court of ‘faithful, honest and diligent’ performance of the duties of Executor, including undue delay in distributing the estate.