This is the 5831st most frequent Russian word.
размером
"Размером" means "in size" or "of the size".
The word 'размером' is used to describe the comparative size of an object (the house) relative to another reference (a football field).
Он купил дом размером с футбольное поле.
He bought a house the size of a football field.
The word 'размером' specifies the physical size characteristic of the box in a comparative sense.
Эта коробка размером чуть больше предыдущей.
This box is slightly bigger in size than the previous one.
The word 'размером' denotes the exact dimensions of the object being described (the table).