File downloading time is proportional to file size.
But you, as the designer, may also have to choose and configure a number of resource files for the applet. Your menu content may be in a separate index file. And you may have a number of graphics files to configure symbols, scrollbars, frames and backgrounds. It's possible, if you have configured everything neatly, to use an initial 10 KB or so for the text file, plus graphics files of only a few kilobytes each. You can have a really great implementation like that.