You must have a very big fridge, Franbern. Do you have all those things in it at once? I also live alone, but my fridge is an under-counter one. It gets quite full after a big shop, but not as full as yours sounds. I have a few large shallow plastic trays (one on each shelf) which I put similar things into. When I need something, I slide the plastic tray out to find it. This means I can pile stuff up in it , and also that I can find what I want without emptying the entire shelf to search. There is space beside each for large items. The trays were sold as litter trays - before anyone says "ughhh!", they were bought new and have never been used as such.
In your salad box^"lettuce, spinach, carrots, peppers, tomatoes, cucumber, celery, sugar snaps, etc."^ I agree with lettuce, spinach, carrots and cut cucumber, but if you are using them within a week, uncut cucumber, tomatoes, celery, and sugar snaps would be OK in the vegetable rack.
"I do a weekly shop - and the large proportion of this goes direct into the fridge., eggs, cooked meats (eg: ham, corned beef), ready made quiche, yoghurts, cheeses, ready made beetroot salad, coleslaw, chicken pieces/meats to be used in that weeks meals, breads (I know they say these should not be kept in fridge. but I find they all keep longer and fresher that way. I use Nimble bread - two slices a day and the occasional treat of a thin begal, but also have a packet of paninis in case someone comes to me for lunch any day"
Bread is very bulky. I freeze paninis. 30 seconds in the microwave will thaw them out, plus a few seconds more if they are still frozen in the middle. Bread freezes well, too, and a few slices can be removed from the still-frozen packet a short while before using (slide a table knife or a spatula between the slices if they try to stick together) , and thawed briefly in the microwave if they need it. I freeze unsliced bread in smaller pieces and freeze it, too, it will thaw out either in the freezer or in the plastic bag it was frozen in. All bread is as fresh when it comes out of the freezer as when it went in. Nimble always dries out even in the fridge, because it has no fat in it - you may find it stays soft better when it has just been defrosted from the freezer
"I also keep cooking apples, eating apples and easy peels in fridge to keep them longer, just putting a couple on the fruit bowl in the Living room to come to room temperature before they are likely to used"
Apples are stored for months at a time without being in a fridge. Are you sure they won't keep for a week at room temperature? I wouldn't have thought of doing anything else.
"Slimmer top shelf, which is difficult for me to reach, has items which I need only occasionally, container with ground coffee for cafetier, a few cola cans, for g.childrens visits, pickles, packet of pastry,"
Cola doesn't need to be stored in the fridge. If you have warning of the children's visits, you could put a couple of cans in to chill before they get there. Pickles do not need to be there - they are deliberately made with vinegar to preserve them, just as jam is made with sugar as a preservative.
"The door shelves are taken up with milk, mayonnaise, a good selection of jams, and marmalades, etc. lemon juice, cold water for pastry, selection of flavourings for coffee, etc. the occasional tetrapack of fruit juice."
Cold water just takes up space, there is plenty in the tap. If you want it colder, put a small amount into the fridge for a while before you start making your pastry, or use that packet of ready-made that is in there. Jams and marmalades are preserves - the sugar content preserves the contents, but once they are opened they need to be eaten within a reasonable time.. I only have one marmalade and one jam open at any time, so that they get used up, and I keep them in a cupboard, not in the fridge.
I think perhaps the changes of temperature as the glass jars are taken in and out of the fridge to use may encourage condensation and the resulting dampness may then grow mould even faster - but that is just a theory.
Another tray on your top shelf may make it easier to use. you could pull it right out and put it on the worktop to find things.