This article is pending update…

Everything jarred or tetra-packeed you see in the shops’ shells (not refrigirated) is possible to keep at home’s temperature, even after jar/pack is opened. Milk is exception. Good idea – if possible, buy little packages, so they can be used at once or use another ½ in the next days.

Jars:
(ex. pesto, tomatoe sauce, confuters etc.. anything scoopable from it).
– get ready, keep jar closed;
– wet the spoon;
– keep it over the gas flame untill last drop evaporates;
– open the jar, sizzle-scoop the matter, close;
– (opt. – spray the bottom of lid with vinagre);

Tetra-Pack:
(ex. tomatoe sauce, cream etc..)
– unfold the pack corner (beak);
– keep it up-side-down (at all the time while used!);
– cut the tiny opening;
– squeez the matter, squeez remainings firmly out the beak;
– fold the beak at least twice;
– keep it tightly closed (ex. paper/tension clipper);

Milk:
So far best option is to buy tiny packs of 125 ml.. 
Opt. milk powder. Evaporated milk can be kept longer.

Leafy vegies:
Keep it in dump towel, inside plastic bag; Or better – eat them now.

Cheese:
..and quite many other thing. To consider: veg oil!
Also depends on cheese. Permasano cheese doesn’t need any treats.
Veg oil keeps things purely sealed, but with one condition – no water should be involved. Slice brie cheese, some onions, keep it for a week dipped in olive oil. Try now the luxurious formage! 

Mayonnaise:
Scoop, keep, scoop, keep…  no problem ever, nothing happens to it over the months.

Eggs:
Keeping eggs in fridge in general is new-age idea. You can store eggs up to two months in room temperature with no worries. Sink the egg into fresh water — if it reaches the bottom, it is good to eat.