Photo for background takes a lot of space (MB)

I want to put a picture for background in an excel spreadsheet. I can do it
but the picture is spread to the whole sheet and gives a file of 2 MB. Is
that a way to :

Put a background for just about 100 cells and make sure the picture doesn't
spread to all the others cells ?

OR

Reduce the amount of lines and columns when I create a new spreadsheet,
presently you can have thousands of lines and columns available. ?

If it can help you, what I really want to do is to put a map in the
background of a excel spreadsheet to be able to say : I have seen that rare
bird in the area of the cell E9 on that map. I also want everybody who is
opening that file to see the map the same way (same size).

Tks

Charles