The following documentation is for Confluence Cloud users
Excellentable can be used within Space and Global templates. However there are some limitations.
Templates have to be saved before adding excellentable macro.
Adding excellentable to unsaved templates shows one of the errors below
Excellentable Macro in Space and Global templates do not render on view mode due a bug in Atlassian Connect framework. We are working with Atlassian to get this fixed as soon as possible. But this does not affect any of the functionalities when creating pages from Templates.