local to module objects and GC

[mnicolet <mnicolet@...>]

Hello.
My application requires some configuration info ( Uh !!! ). Usually, I do
that by defining one lua table structured to meet the particular
requirement, and one or two ´visible´ ( interface ) functions to exploit the
table data. To not polute the name space, I try to declare as many objects
as possible as locals to the module. An example
-- module bla_bla : stores data for ...
local datatable = {
        -- config stuff here ...
}
local auxiliary_func = function( bla, bla )
 --
end
-- use this function to get ... the params are ...
mainAccessFunc = function( foo, bar )
   -- exploit the datatable contents, may be calling auxiliary_func ... etc
end
-- use this function to validate .. the params are ...
anotherAccessFunc = function( bar, foo )
--- etc
end
So one can ´require´ or ´load´ the module, but only the interface
function(s) are in the global space.
Of course, it´s not any novelty. And of course, it works.
What is scaring  me is
Why the local objects are not collected ? where are they stored ?
I am asking to satisfy my curiosity, and to learn a bit more.
Marcelo
PS searching the internet, I fall once and again to scripting language
pages. I allways pay a bit of attention, comparing them on the fly with Lua.
Sometimes, some features are appealing. But after a few minutes, I
counterbalance the nice
feature(s) against Lua´s sintax, grammar, power, speed, small footprint, etc
and ´come back´ to
Lua
Thanks to the team. They give us a hard to beat tool !!!