In the fridge or not in the fridge?

Eggs - no
Ketchup and HP - no
Mayo - not fresh made. No PseudoHellmans
Grapes and other casual pick-one-up fruit - yes in the summer
Onions - no
*White wine you don't plan to drink soon - no
Opened jam and marmalade - no
Tomatoes - yes
Butter in winter - no
Pickles and capers in jars pickles no , never bought capers so no sure
Easy garlic and tomato puree in tubes - no

Eggs : not in fridge but in a cool place
Ketchup and HP : not in the fridge when I was a kid, but these days it says o the bottle that it should be
Mayo - not fresh made. PseudoHellmans: definitely in the fridge
Grapes and other casual pick-one-up fruit - definitely not in the fridge
Onions : why would you?
*White wine you don't plan to drink soon : white wine that you plan on drinking soon should be refrigerated, whether it's open or not! If you're just going to use it for cooking it's OK at room temperature but use a vaccum stopper:
Opened jam and marmalade : only apricot which has a tendancy to go off quicker than the others: jam is full of sugar so is OK at room temperature (especially if you have my husbnad eating it: he'll polish off a jar well before it can go nasty:
Tomatoes : flavour ruined by fridge storage
Butter in winter : fridge
Pickles and capers in jars : not in the fridge
Easy garlic and tomato puree in tubes : definitely in the fridge

Eggs- out of fridge
Ketchup and HP- fridge
Mayo - not fresh made. PseudoHellmans- fridge
Grapes and other casual pick-one-up fruit- fridge
Onions- cupboard
*White wine you don't plan to drink soon-unopened in cupboard
Opened jam and marmalade- fridge
Tomatoes- fridge
Butter in winter- on side in dish
Pickles and capers in jars- opened in fridge
Easy garlic and tomato puree in tubes- opened in fridge

Eggs need to go in the fridge in the USA because they have been thoroughly washed before being sold refrigerated in supermarkets and the 'bloom' has been washed off which means the permeable shells can draw in bacteria.

Eggs in the UK are not processed in the same way so are safe to keep out of the fridge - as are eggs from your own chickens.

https://eggsafety.org/us-refrigerate-eggs-countries-dont/

Eggs, onions, tomatoes, butter = not in fridge

Tomatoes lose their flavour and onions don’t need to be stored in a fridge. The dairy products I can see why some still would but they’re wrong!

If you live in the UK, eggs don't need to go into a fridge as they're not at risk in the same way that battery eggs produced in the US are.

Just to clarify, I do keep tomatoes in the fridge but I take them out a few hours before I plan to have them. Sometimes I even add some olive and salt whilst they get to room temperature 😅

You don't have a fridge??

Tomatoes should never be refrigerated and eggs should always be room temperature for cooking.

Everything in fridge except ketchup, brown sauce & jam & mayo

All of this. Except if you put onions in the fridge, they don’t make your eyes water when chopping. This has been a game-changer for someone (me!) who used to wear a full-face motorbike helmet when chopping onions!

Yes to all.

In our house:

Eggs - fridge
Ketchup and HP - cupboard
Mayo - not fresh made. - fridge
Grapes and other casual pick-one-up fruit - fridge
Onions - cupboard
*White wine you don't plan to drink soon - cupboard
Opened jam and marmalade - fridge
Tomatoes - fridge
Butter in winter - butter dish on side (fridge in hot weather)
Pickles and capers in jars - fridge
Easy garlic and tomato puree in tubes - fridge.

Eggs not in the fridge!! I make a lot of bread and the eggs have to be room temp.

I'd put everything else in the fridge, assuming you mean opened condiments. Wine - as I buy a case at a time I store that in the bottle rack and put one bottle in the fridge ready for opening.

My MIL swears tomatoes are better out of the fridge but I prefer them cold.

You only store cold things which would go off quickly or grow mould.
Preserves are called that for a reason. Jams are such high sugar to PRESERVE the fruit and stop it going off.
I bet you even put decent cheese in the fridge eye roll Do that in a traditional French house and you’ll get an appropriate response.

What time do you tend to start drinking on a Friday morning?

FRIDGE
Grapes and other casual pick-one-up fruit
Tomatoes

FRIDGE ONLY WHEN OPENED
Ketchup and HP
Mayo
White wine
Opened jam and marmalade
Pickles and capers in jars
Easy garlic and tomato puree in tubes

OUT OF FRIDGE
Eggs
Onions
Butter

In the US, eggs need to be refrigerated because of the way they're processed. Over here, we don't remove the natural protection from the shell, so we don't need to keep them in the fridge.

Created by soothsayers, around the 9th century I believe.

Tomatoes in the fruit bowl
Eggs in a wire chicken on the counter
Salted butter in a butter dish, unsalted in fridge
White wine in garage until Friday morning

Everything else on your list in fridge

Assuming it's already been opened, this is what I do:
Eggs - fridge
Ketchup and HP - fridge
Mayo - not fresh made - fridge
Grapes etc - fridge
Onions - fridge
Tomatoes - fridge
Easy garlic/tomato puree in tubes - fridge
capers in jars - fridge
Shop-bought jam/marmalade - fridge

Homemade jam/marmalade - not fridge
Pickles in jars - not fridge
Butter in winter - not fridge

Assuming it's unopened:
White wine you don't plan to drink soon - not fridge.

I wouldn't put eggs, tomatoes, preserves (jam, marmalade, pickles etc) or most fruit and veg in the fridge, or butter except in Summer. British eggs don't need to go in the fridge and you don't buy them from a refrigerated cabinet in the supermarket. I'd only buy proper preserves which are made fully with sugar, salt or vinegar. All this stuff cooks and tastes better without being in the fridge.

Ancient as in pre-electricity? 😂

There are actually ancient bylaws in many towns and cities in the UK banning the storage of tomatoes in the fridge because its such a heinous thing to do.