Raised bed tables

I think it  all down to ones preference and I'm not going to tell you how to suck eggs but instead I will tell how we do our raised beds we make our raised beds aprox 12 inches high 6ft long we dig over the ground fill the ones we need to grow brassicas with half well rotted manure and half compost to top of 

some veg we don't need manure like parsnips so we dig over the bed and fill it with compost usually its spent compost from our tomato or other things when we  empty  the greenhouse and pots sometimes if we haven't enough used compost we buy whatever's compost is on offer

also I made brackets to fit the raised beds for environment netting on every raised bed obviously I don't know what your soil is if heavy or light soil  I ended up making twenty raised beds out of re-claimed decking  I treated all the timber before making the raised beds but I have found raised beds to be much easier than open ground sowings and planting the only open ground plantings we do  now are runner beans main crop potatoes and some broad beans and peas the early potatoes go in the raised beds like all other veg

I'm going for a salad raised bed this season if it stops raining for a couple of days  i also built a fruit cage more or less on the same plan  as my raised beds with boards round the cage and filled with manure round the bushes

i have to say making the raised beds did take me a week to make and another week to install  them down the allotments but then being retired time was not an issue hope this reply helps you and good luck with the raised beds

I have some pallets on legs and use pallet collars on the pallets, then weed fabric on the sides and bottom and fill with compost etc. the collars are about 6 inch high but you could put two collars on if required.
Size is the standard 1200 by 800

Salads would grow in 6ins depth, but most of the others would be better with 12ins. Unless you fancied long parsnips I don't think you would need a deeper bed for the others tbh.
Runner beans and peas, the shorter varieties would grow in 12ins depth as long as they were watered enough. Good luck

Salads would grow in 6ins depth, but most of the others would be better with 12ins

So far I have grown strawberries, stumpy carrots, salads and beetroot

Thanks these posts help clarify my thinking. Four beds with two at 6 inches and two at 12 to start with, see how it goes. I've concluded that 18 inch deep is not really practicable. Choice of seed is next, I have always grown Autumn King carrots may be better with shorter ones. Will have to consider what to do about Leeks. MoS mentions watering which makes we think Celeriac may not be best choice, but I must have some Swede. With the smaller quantities I'll be growing I will have to look at things that are not easy to find or expensive to buy.

 "a 7' high structure full of beans in the height of the growing season will act like a sail in high winds,"
At 5ft 4ins and 8 stones I'd be soaring off with it. Years ago I was all set up to do a parachute jump but on the allotted day I was not allowed as it was too windy. Dwarf beans definitely.