Most microSD cards come with a full-size SD adapter. I've got gobs of them around.
The reverse of what you're going for, but if you use this to use a microSD in your gopro, you can pop it straight into your tablet and be set.
Alternatively, if your tablet supports USB-OTG, you could use a
USB-OTG adapter and USB SD card reader, but that's definitely the long way around the problem.
If your tablet doesn't support OTG, you can flash an OTG-friendly kernel or root and install an app called stickmount that'll let you use USB drives (and USB SD card adapters) with a USB-OTG cable.