make it smaller in terms of file size, not the physical dimensions. You can do this several ways...

In your scanning software (or digital manipulation software) change the resolution quality, i.e. the pixels per inch. If the file is not a .jpg, then save it as a .jpg, this can reduce the size.

Sometinmes it helps to change the scanning resolution. For display on most computer monitors, any resolution over 150 dpi is wasted. (I said "display" not printing.)

You should always crop out any blank spaces around the object you are scanning. If the scan is 4" x 4" and the object being scanned is only 1" x 1" then the file size of the 4x4 is 4 times the size of a scan of just the object. Get rid of wasted surrounding area.

I hope this helps,

Jim