Having them a smaller size will reduce file size and will still make it readable on a tablet with no problems.
I could go through each file and change the size and then save them as JPEGs but at 125 pages that's going to take a substantial amount of time.
Instead, do a BATCH conversion:
1. Go to FILE> SCRIPTS > IMAGE PROCESSOR
2. Select the FOLDER your files are in, set SAVE in SAME LOCATION (don't worry it will make it's own new folder), check off SAVE AS JPEG and RESIZE TO FIT and fill in the size you want the pages to be-- in my case I reduced them to half their original size and set the quality to 7.
Click on RUN-- the computer will race through the files and create its own sub folder with the new files.
3. That's all there is.
You'll now have a folder with copies of all your files now reduced in size, all in a matter of about two minutes.