Cable having a coil like loop
This is OK. 

It perhaps looks untidy.

With thick cables like that, and closely spaced terminals, it's essential to have an extra length of cable between them so the cable is flexible enough to be able to actually get it into the terminals.

At mains frequencies, the extra inductance of that loop, in the air, is insignificant.

In electrical distribution, the extra resistance of that loop is insignificant, compared to the other resistances in the path.