I often see humans telling us the amounts we should or should not eat and often those amounts are wrong.

A baby bunny cannot eat the same amount as an adult bunny and a giant bunny cannot eat the same amount as a dwarf or mini bunny.

Regardless of size and age one thing is general:

we should always eat at least our size in hay, if it is more the better.

A baby or young bunny which is not yet on a complete diet, that is, which does not eat greens and herbs daily, should always eat the amount of pellets indicated on the package (do you know how to choose a good pellets? Don´t? See here), usually between 50 and 80 grams, depending on the brand and so as not to give it all at once you can divide this amount by two and give it twice a day.

Normally it is said that greens (do you know which greens we can eat as much as we like? See here if you don´t  remember) should be the equivalent of the size of the head of the bunny, of course when we are in nature that is not the amount of greens that we eat, but we also eat a lot of grass and herbs and that helps a lot to wear down the teeth, as when we are in the house of humans we don't have access to this, so it was generalized that this amount would be indicated. The truth is that it has no basis, if you want to give us a bowl full of greens we will eat while we are hungry and when we have a full stomach we won't eat any more. There are vets who even say to give greens at will but only for a certain period of time each day, for example, leave a very large bowl full of good greens at our disposal for 30 minutes and then don't give any more. It is up to you to look at your bunny and see if he needs to eat more or if he is happy to eat hay.

If with the greens you can add forage or fresh grass even better, because in this way they are also wearing down the teeth, as I explain in the part about the grass (see here), this  fresh grass has properties just like hay which help in the wearing down of the teeth, There are many countries in which the bunnies eat much more fresh grass, or semi-dry grass than hay, this is because it also helps in the wear of the teeth and has fibre and in this case if the bunny eats more it only does him good, because it ends up being as if he was eating hay.

You have seen that I am not very much in favour of pellets, (if you want to see here about it) but humans love to feed the rabbits, so if your bunny has a complete diet, with greens and herbs, the pellets are just a complement, a little extra. Giving 1 or 2 tablespoons a day is ideal, there is no need to give more. 

Herbs often cause some confusion, there are humans who mix them in the hay, others in pellets, you don't need to mix them in anything, if they are fresh, you should apply the same method and ideology of the greens, you can even mix them with the greens and make a meal for them, but if it is dried, it is not necessary to be in such quantity. Normally I recommend 1 table spoon of dried herbs for the rabbit, if the mix of herbs is of 3 it will be 1 tablespoon of each herb, making a total of 3 table spoons of herbs per day, as the herbs are to be given in moderation and only as an extra complement to the diet (remember that there is no scientific evidence as to their application in rabbits, it is all in the holistic field and in this case in the field of alternative medicine in the field of rabbits, or in a simpler way, the herbs of our grandmothers, if you don´t remember see here), it is not advisable to eat too much, the rule is normally 2 or 3 different herbs per day which makes 2 or 3 soup spoons of herbs plus 2 table spoons of the hay which is left at the bottom of the bag, all mixed in a bowl. 

In the case of the giant or large rabbits (rabbits which weigh more than 3 kilos) the quantity has to be much greater and in this case to keep a large rabbit,you have to give it a lot of greens or you have to give it pellets every day.

The greens for a giant rabbit can be given the equivalent of twice the size of its head,ears included,twice a day,or in this case use the method of the giant bowl full of greens for 30 minutes and then no more greens.

In relation to herbs it is the same thing, if they are fresh you can add them to the greens and give them as if they were greens, if they are dried you can double the original quantity, or instead of 1 tablespoon, be 2 tablespoons.

As these bunnies need more food, so that they can maintain their weight and not get too thin, they can and should eat pellets every day, the amount can be the amount indicated on the package or between 50 and 80gr. If your giant is fine without that amount of pellets, then leave everything as it is, now if he is getting thinner or if you can not maintain the weight, give more pellets, (usually it is indicated 25gr of pellets for each kg of rabbit, or if your giant weighs 4kg he should eat 100gr of pellets per day), the rabbits are not all equal, never forget that.

Independently of the size of your bunny, fruits and vegetables should always be given in moderation and in small quantities.