Overview En.sb and En.toc are community-made mod files commonly used to enable custom audio, UI text, or localized content in Need for Speed Rivals. When implemented correctly they let players replace or extend in-game voiceovers, menu text, and other packaged resources, bringing fresh immersion or language support to an otherwise static installation.
If you want, I can provide a concise install checklist or suggest trusted community hubs where these kinds of NFS Rivals mods are commonly shared.