This project demonstrates an error in fastexcel when creating a formatted excel table with an ampersand in one of the column headers.
Checkout the project and simply change the constants with the output pahts. Then, run the main method. Two files will be created: First one is a working excample of the excel file. The second one is basically the same as the first one, with only change to have an ampersand in one of the colmn headers.
When you open the second file, excel reports an error and the table is not formatted. The first file works fine.
This project belongs to the reported issue in the fastexcel-project: dhatim/fastexcel#445.