Got Error message (OutOfMemoryError) when I just started Matlab. Why?

Hi, this sounds a stupid question... I start my Matlab session, and barely defined ore or two variables and a full screen of error message (see attached picture). Do you know what that says? Thanks in advance!

Also, those numbers in the commond history window were not keyed in by me. I don't know where they came from? Besides, my previous commonds almost all disappeared!