page 60 of the on site guide shows cables running vertically or
horizontally from accessories.

Is it really OK to run them between sockets horizontally?

I've never seen it done - people usually run up from the floor (or
down from the ceiling) to each sockets, even when a horizontal run
would be easier. It would save a lot of effort in our kitchen and
study to run horizontally between sockets, just dropping down at each
end.

If this OK?

Cheers,
David.