What does this code do?

[Codger]

I've seen this in a couple addons but haven't been able to find any info on what it does:

local frame1 = {}
myAddon.frame1 = frame1

I'm guessing it's another way of setting up a namespace?
What I am doing in an addon is:

local addonName, addonTable = ...
function addonTable:doSomething()

which requires me to preface everywhere I use doSomething() with addonTable.
Curious if this is a better way?