To increase the Memory Allocation:
1. File | Preferences | Running | Size of Log Buffers (KB)
Note: Increasing this log buffer value will make the amount of memory of the Java process that runs the GUI grow.
Instead of the above change it is highly suggested to access any large logs directly with a third party text editor (logs can be found in confs/*/logs folder) as not to consume too many resources on the local workstation.