Normally, because Blu-ray movies are of really high quality, their sizes are also quite large, ranging from 15GB to 30GB. So if you to rip Blu-ray to PC using VideoByte BD-DVD Ripper, thanks to its in-built video compressor, you can easily compress the Blu-ray movies to smaller sizes but keep in original quality.
Also, you can try HandBrake to compress MKV Blu-ray videos after ripping with other software like MakeMKV to save your device storage.