Originally posted by Newfie taken in RAW large format
My understanding is that a RAW file will always be at whatever the image sensor base resolution is, such as 10MP for a K10D, 16MP for a K-5, 24MP for a K-3, or 36MP for a K-1. The reason is that these files have every piece of information recorded from every pixel, and will be on average maybe 10 times the file size of a jpg of the same resolution. If your camera has lots of pixels (don't they all these days?) and you have 700 RAW pictures, you are going to need a considerable amount of storage space indeed.
Where are you downloading them from? What is the storage capacity of that device? Could you consider using a 64GB or larger thumb drive as the target storage device?
Regarding the difference of jpg vs. RAW, here's a chart I ran across that shows how RAW files have much finer tone resolution than jpgs:
RAW files can also capture much finer gradations between colors. Bottom line, they give you much better images, at the trade-off of needing a lot of space to store all that image info. No free lunch.