How many tons of manna must have fallen, in order to feed millions for 40 years?

Was the manna prepared fresh everyday in heaven before it fell, similar to the weekly preparation of the shewbread?

Leviticus 24:5 And thou shalt take fine flour, and bake twelve cakes thereof: two tenth deals shall be in one cake.

  6 And thou shalt set them in two rows, six on a row, upon the pure table before the LORD.

  7 And thou shalt put pure frankincense upon each row, that it may be on the bread for a memorial, even an offering made by fire unto the LORD.

  8 Every sabbath he shall set it in order before the LORD continually, being taken from the children of Israel by an everlasting covenant.

The manna came daily, and in the morning they were given bread.

But in the evening they were given flesh to eat.

What was that flesh?

Exodus 16:4 Then said the LORD unto Moses, Behold, I will rain bread from heaven for you; and the people shall go out and gather a certain rate every day, that I may prove them, whether they will walk in my law, or no.

  8 And Moses said, This shall be, when the LORD shall give you in the evening flesh to eat, and in the morning bread to the full; for that the LORD heareth your murmurings which ye murmur against him: and what are we? your murmurings are not against us, but against the LORD.

  12 I have heard the murmurings of the children of Israel: speak unto them, saying, At even ye shall eat flesh, and in the morning ye shall be filled with bread; and ye shall know that I am the LORD your God.

Apparently it might not have been the quails, because that seems to have been a special one time thing, late on?

Numbers 11:4 And the mixt multitude that was among them fell a lusting: and the children of Israel also wept again, and said, Who shall give us flesh to eat?

  13 Whence should I have flesh to give unto all this people? for they weep unto me, saying, Give us flesh, that we may eat.

  18 And say thou unto the people, Sanctify yourselves against to morrow, and ye shall eat flesh: for ye have wept in the ears of the LORD, saying, Who shall give us flesh to eat? for it was well with us in Egypt: therefore the LORD will give you flesh, and ye shall eat.

  19 Ye shall not eat one day, nor two days, nor five days, neither ten days, nor twenty days;

  20 But even a whole month, until it come out at your nostrils, and it be loathsome unto you: because that ye have despised the LORD which is among you, and have wept before him, saying, Why came we forth out of Egypt?

  31 And there went forth a wind from the LORD, and brought quails from the sea, and let them fall by the camp, as it were a day’s journey on this side, and as it were a day’s journey on the other side, round about the camp, and as it were two cubits high upon the face of the earth.

  32 And the people stood up all that day, and all that night, and all the next day, and they gathered the quails: he that gathered least gathered ten homers: and they spread them all abroad for themselves round about the camp.

  33 And while the flesh was yet between their teeth, ere it was chewed, the wrath of the LORD was kindled against the people, and the LORD smote the people with a very great plague.