I have 5 columns with a list of items in each (all text entries). I want to
create a sixth column with every permutation of items from each column.

I started by inserting a formula where I held all but one cell as an
absolute reference. When I filled down, the one cell that remained relative
changed and I had the first set of permutations; 4 items (the first one from
each of the first 4 columns) stayed the same, the last item changed. This
works fine but it is time-consuming and difficult given the number of items
in each column (one column has 20 items).

I tried pivot tables but it doesn't seem as if they are meant for this (I
might be wrong).

Please let me know what is the best way to do this.

Thanks,

Bram