MySQL Table can crash for a variety of reasons, such as an abnormal shutdown or a power failure. This can also occur if the operating system run low on disk. It can occur on Windows on WAMP Server too.
MySQL Table Crash fix (*nix System)
To fix this issue SSH into your server and make sure you have ample disk space, for that first check disk space
if ample disk space is available then issue following command
mysqlcheck -uMySQL_USER_NAME -p --repair --all-databases
It will ask for a password provide, and it will repair it.
MySQL Table Crash fix WAMP Server (Windows)
If you are running WAMP Server on Windows easiest and quickest fix is to restart all services, provided you have adequate disk space available.