Quick Google:
So What Is It?The quick answer is that it’s part of the GTK+ library used by a number of cross-platform applications, perhaps the most well-known of which is the Pidgin instant messenger client.
As the name implies, the file is used to store a list of the most recently used files. In the case of Pidgin, this comes into play when you are transferring files over IM, and that’s when the file will appear again.
Note: this is actually a known and reported bug in Pidgin, but sadly the developers aren’t terribly responsive when it comes to annoyances. Pidgin seems to go for long periods of time without any updates, but we still use it because it’s open-source, cross-platform, and works well.
howtogeek.com - What Is .recently-used.xbel and How Do I Delete It for Good?