Pass reference to datatable into function

I wish to pass the name of a datatable into a function, such that the function can then retrieve values from said datatable. I tried passing the name as text, but it didn't work. I've also spent a fair amount of time looking around the web for different ideas, to no avail.

I suspect I need to pass the name as an object reference or perhaps a control, but i've never used OO before (although i've read a fair bit about it) and so i'm struggling. Is anyone able to point me in the right direction?

TIA