Hi, Dona -
First of all, welcome to GroceryCRUD! Hope you have looked at all the exciting features of this add-in software.
Okay, now for your question. Is it possible to use GC for arrays only?
The answer is NO. GC is designed to provide CRUD capability for tables, not arrays. Also, GC multi-select is used for input to be processed elsewhere.
In order to use multi-select for an array where the data selected is processed in that same interface, you would best need a javascript framework with grid-control capability to handle that requirement.
Ed