M code syntax creating table

Hello all,
I've been looking at introctions to M and have been trying to create this

= #table ({"A","B"},({1,2},{3,4}{5,7}))

Which I think should give me

A B

1 2
3 4
5 7

But it don't. What am I doing wrong? I haven't attached anything as but can, I have been able to create blank using

#table ( {},{}), which I notice only has the opening and closing parenthesis. Any help or pointers to more information gratefully received.

Richard.