That things

The only time this is used is with a noun that is technically singular, but denotes multiple objects, for example:

That herd of deer is trampling my flower bed.

That group of boys is rowdy.

There is a kid program. In it, a boy is holding a bowl of eggs and a box of salt, and his friend is telling him, "put that in the fridge."

Is this also a correct usage for that?

onizoIs this also a correct usage for that?

Yes. Everything the boy is holding is grouped into the amorphous concept of "stuff".

Put that (stuff) in the fridge.

CJ

Yes, because the friend probably only meant the bowl:

Put that (bowl) in the fridge.

It's unlikely that he's being asked to put the salt in the fridge.

But if that's what the friend meant—put everything you're holding into the fridge—the phrase still works:

Put that (i.e. those things) in the fridge.

In this case, you probably most of time wouldn't need to use "those or these" much, right?

Actually, you wouldn't need those or these at all, what do you think?

onizoIn this case, you probably most of time wouldn't need to use "those or these" much, right?

If you mean in the case where someone is holding a lot of stuff, then you're right. You can call "all that stuff" simply "that".

Someone has helped himself to a heaping plate of goodies at a buffet. He has a plateful of different meats and salads and vege

CalifJimYou would say "Are you going to eat all that?", not "all those".

@onizo, this speaks to the other questions you've have recently about unit vs. mass nouns regarding food.

onizo: you probably most of time wouldn't need to use "those or these" much, right?

Actually "Put those [things] in the fridge" would be perfectly fine.