Yeah I do this all the time. Either add such data in the data tab or build a little admin interface for it.
Here’s a simple example. Let’s say you want an array of things for representing the Days of the Week.
Make a data type “Day of Week” give it fields for Name (a text), index (a number), and anything else u want to reference about those things. Now make 7 of them.
Boom. Now you have a system level object that is a list of Day of Weeks. To access it, Do a search for Day of Weeks. This will return that list, see?