Here is a tool that was made by a friend of mine (tal). He's also a member of this forum (find him and spam his PM box!) but he's either too modest or too lazy to log in and share it with the rest of you. I like to think it's the modesty....
Anyways, here is a tool that will trim your savegames by removing dead characters, battle history, character histories and such. It was designed to work with EU:Rome with the 2.32c patch of Vae Victis, and the EPIGONI MOD, Version 2.01b. It should in theory work for other savegames using Vae Victis (unless the mod made some major changes to the savegame format...), but it is what it is. As an example, a 43.5mb savegame was trimmed to 9.7mb and worked as it was supposed to.
Here's the link for the download: