The issue is related to the 32-bit version of Java software installed by default in your operating system. It has the limitation of about 2 GB of RAM available for CafeTran. To overcome this limitation, you need to download and install the 64-bit version of Java for 64-bit operating systems (http://java.com/en/download/index.jsp).
After 64-bit Java installation, go to the Options panel in the menu Edit, choose the Memory tab and increase the default value of 1024 megabytes to 2048 in Java Memory field. You can increase this value even more but do not go over the actual RAM memory in your system.