You can select the maximum memory that Wordfast Pro will use to ensure you can open and work with large files with ease.
To select memory preferences:
Open Wordfast Pro and click Edit
> Preferences > General > Memory Preferences.
The Memory Preferences dialog
box appears.
Select the amount of memory Wordfast Pro will
use on your machine and click OK.
Note: Maximum memory is the Java heap size. If the memory size
selected here is more than the available memory, you may get a Java heap
size error.