Huge memory Allocation when using EPPlus Excel Library

Question

Context

I have been using EPPLUS as my tool to automate excel report generation, using C# as the client language of the library.

Pro

Answer 1

Modern Excel files, ie, Xlsx files are zip-compressed, and often achieve compression down to 10%. I just uncompressed a 1.6MB file I generated using a similar tool and found it extracted to 18.8 MB of data.

You've got a 0.138 GB file that is using 1.370 GB of memory, which is almost exactly 10%. The uncompressed representation in memory is what is eating your memory.

If you're curious, you can use a tool like 7-Zip to extract the Xlsx files, or you can rename the file to end in .zip and browse it in Windows.