In Confluence, there are no drop-down macros for the user so the same can use it for form purposes or fill tables with specific information, so the same will not be needed to be manually inserted into the table's cell.

A quick example of use case is when you have a table with a particular value that can be tied to different options (companies, for example) in which the user could quickly change it according to the macro configuration options.

This is a suggestion to create a Drop Down List macro for Confluence.