This allows you to browse the file list without extracting everything first.
Often, creators include a .txt or .md file inside the archive explaining what the contents are. Tall_Diamond.7z
It may be a file named by an individual for personal storage. The name "Tall Diamond" might refer to a specific project, a Minecraft build (common for "Diamond" related names), or a 3D model. This allows you to browse the file list
If you haven't already, install the 7-Zip utility . Tall_Diamond.7z
If you are looking for what should be in that file or where it came from, here are the most likely possibilities:
This might help me track down the specific context for you.