Nested loop to concatenate 2 columns of data

Hi,

I think I just need a basic Nested For Loop code...

I have a list of in column A, from A1:A537

and another list in column B, for B1:B50

I want to add a column that concatenates,

each item in Column A to B1 (so 537 rows), then again each item in Column A to B2, another 537 rows, etc.. this loop is repeated 50 times, one for each name in column B.