I fontly searched to find if seven is the most goals Arsenal scored in a match along with that 7-5 victory against Reading this year. After analyzing all the scores from their history, found their best in a single match was in 1932/33 season, a score of 9-2 against sheffield United and a 9-1 victory over Grimsby Town in 1931. Another score that amused me was a 6:6 draw against Leicester city. Best high scoring spree I have witnessed till now is the 4:4 draw of Sweeden against Germany recently.
Most by Arsenal in a single match