That's impossible to tell. Qlikview will use (potentially a lot) more RAM than the size of the uncompressed amount of data in the reloaded document. How much depends on the amount of source data you load and what calculations need to be made to get the final results. You could process many gigabytes of source data and manipulate this data so your final document contains only about 500 MB of data. Or you could extract 50 KB of source data and generate 500 MB from that.
