Compress photos within Excel
Compressing photos can reduce the file size of an Excel document. To compress one or more photos, select a photo, and then select the "Picture Tools: Format" tab. Above "Adjust" select "Compress Photos". If you want to compress only the selected file, ensure "Apply to selected pictures only" (2007) or "Apply only to this picture" (2013 & 2010) is selected. Click "OK".