Most people don't have a good understanding of what Gallery does or is. There are no real original files there. Gallery finds media on your phone or tablet and indexes those items into a cache of images, but not the actual files. The actual files are somewhere else.
Depending on what you want to share between the 2 pretty much any non Samsung product will do what 2 Samsung devises will unless you use Samsung program called Kies. Kies, unfortunately, isn't very good.
My best suggestion is to get a DropBox account and have it send your media to the cloud so it will all be available on both devices.