The board of review shall have the power to correct or amend the assessment roll and to increase or decrease any assessment or valuation of taxable property, may strike therefrom any property wrongfully listed, or add any property rightfully taxable, either on its own motion or at the request of any person. Any person considering himself aggrieved by reason of any assessment may complain thereof either verbally or in writing to the board. The board may establish reasonable regulations for the conduct of its hearings, require the filing of a brief written memorandum of the arguments by those appealing to it, require any appellant to appear in person or in writing and otherwise provide for expediting its work. The concurrence of a majority of the membership of the board shall be necessary to decide any question. The assessor shall make any changes, additions, or corrections to the roll directed by the board of review. Thereupon the board shall complete and adopt the roll and a majority thereof shall endorse it as provided by law. When so endorsed, the roll shall be conclusively presumed by all courts to be valid and shall not be set aside except for causes mentioned in the general laws. The omission of the endorsement or any other formality herein prescribed shall not affect the validity of the roll. A summary report of the assessment roll shall be delivered to the council by the assessor immediately thereafter.