Due to the fact that WAP devices have very little memory, there is a limit to how big each WML deck can be. To make things interesting, there is no standardized limit, so it varies from browser to browser. The list below shows the limits on some browsers.
 
Note that these limits note the size of the WML deck in its tokenized/compiled/binary form, in other words not the plain text XML code that you most likely send out from your server, but the compiled form which the gateway passed along to the WAP device. An uncompiled WML deck can be quite large, and then end up as a fairly small compiled deck once it passes through the gateway.