We transpose the list so that the Nth column is the Nth list of the entire array Column n = l[n-1])
headers = ['Column 1', 'Column 2', 'Column 3']
l = [[1, 2, 3],
[4, 5, 6],
[7, 8, 9]]
table = tabulate.tabulate(list(map(list, zip(*l))), headers=headers, tablefmt="github")