If you have this file and want to know what it is without playing it, you can try the following:
Files named this way are usually generated when someone uploads a video to a cloud service or messaging app. How to identify the content:
If you can describe a few details about the footage, I might be able to help you identify the actual title!
The .mkv extension (Matroska Video) indicates this is a high-quality video file that can hold multiple tracks (audio, subtitles, etc.).