There is no artificially imposed limit, although of course your browser may enforce a limit on the memory available to Snap!.
In the reply that mentioned 100, there is a limit of 100 to the number of items that will be displayed at once in a list-view variable browser. In the bottom right corner of the display there is an arrowhead you can click to select which 100 elements are visible. This is a limitation to prevent slowing down the rest of your program. If you choose table view for your list, you can see all of it at once. (The reason table view can handle a much larger display is that the items aren't editable in table view as they are in list view.)