The Back-Up RAM Cart was released in all regions specifically for games that requires large amount of "blocks" to save data. Such games like Shining Force CD, Sensible Soccer and Eternal Champions for example could fill up the amount of blocks on the Mega CD and or, won't save at all because the space is full.
Unlike the widely released versions for the US and Japanese regions, the European version wasn't developed by Sega. Instead it was released by a third party hardware developer called Fire. Very little infomation is known about this version and the company itself. The version itself is extremely hard to find and the images you see above are the first scans of the box and cart ever to reach the internet. So thank you very much to Tim Smith and Kailey Strowger for them.