If TOPCAT fails during operation with a message that says something
about a java.lang.OutOfMemoryError, then your heap
size is too small for what you are trying to do. You will have to
run java with a bigger heap size using the -Xmx flag.
Invoking TOPCAT from the topcat script you would write
something like:
topcat -Xmx256M ...
or using java directly:
java -Xmx256M ...
which means use up to 256 megabytes of memory (don't forget the "M"
for megabyte). JVMs often default to a heap size of 64M.
You probably don't want to specify a heap size larger than the
physical memory of the machine that you are running on.
There are other types of memory and tuning options controlled
using options of the form -X<something-or-other>;
if you're feeling adventurous you may be able to find out about these
by typing "java -X".