Here's a link to a great guide for partitioning written by one of our members ->GParted partition guide for Linux and Windows users
@h2f had it absolutely correct
the swap area is the key for systems with little RAM
The reason your system crashes is more than likely due to running out of memory when browsing. Creating a swap area provides extra memory for your system when needed. The down side it will be slower that physical ram, the major upside your system probably will be more stable.