the reason they were so big was so that they could fit different rooms inside.I was taking a tour inside a pyramid once and I couldn't believe how many rooms there was.OH... I was completly wrong. I stopped in 4 yeah that's right 4 different rooms. There was the King's chamber, the Queen's chamber' the "keepings" chamber and an unfinished room. They were connected by tons of feet of tunnels. I even saw places were stuff used to be. Grave robbers would use special to find a way in and leave with as much as they could carry. So big in size outside, but on the inside so little space used.
Oh yeah I almost forgot 1 Limestone block = 25 refrigerators (I couldn't believe it when I heard it to.)