power diagrams

What happens during the execution of copying, like:

set ls to ()
'tell app "finder" to copy (items of desktop whose label index is 3)
to ls
?
how many cpu-power is needed to find and then, to copy results to a
list if there are up 300 pieces in location x?
Someone own diagrams to see ?? please don't be sheepish!

seems that my last applescripts consumes alot of ram. Since i'm only
applescripter with poor knowledge of shell scripts, i would know to
proceed next. I use extensively handler, repeats and properties, with
dialogs, ect. but nevertheless. I'm in trouble with applescript.