Hi Roscop,
I grow most crops at equidistant spacings and taller plants such as peas in rows as it is easier to provide adequate support for them.
Joy Larkcom gives a rule of thumb for determining equidistant spacing of adding the row and plant spacings together and dividing by two.
We all want to get as much as possible into our available space. But bear two things in mind here, closer spacing results in a smaller plant which is fine if that is what your after. Secondly overcrowded plants are more susceptible to pests and disease.
You can use close spacing deliberately so you can harvest small crops thinning to allow what remains to grow into larger crops, i.e., Carrots, Beetroot, etc.
Don.