EpicTable allows you to choose the folder where your data is stored. Why would you want to do this? Let's say you want to use one computer to do your prep and another to actually run your game. I do this all the time--I prep on my desktop, but I run the game from a laptop. So I store my EpicTable data on Dropbox. You could use Google Drive or a network share too. The main thing is that both of your computers have access to this folder and that you're not running EpicTable on both at that same time, because they'll fight over the files in that folder.
Click on the little gear icon in the lower right corner of the Start Page, the dialog that comes up when you first launch EpicTable. In the screen that follows, select the folder where you want your EpicTable data. If it's an empty folder, EpicTable will copy everything over for you--and it's really best to let EpicTable do that, rather than trying to do it yourself. If there's already EpicTable data there, it will just switch to that folder and work with what's there without copying anything.
One final word of warning. Some of these folder sync mechanisms have some latency to them, so you can sometimes notice a slight lag the first time you set this up if you're creating a brand new folder. I create an empty folder and let Dropbox do its thing for a couple seconds, then go select that folder from EpicTable.