Like Thomas said, that's normal if you configured PHP like that.
If you want LSWS spawns LSAPI PHP processes on demand, you can remove
PHP_LSAPI_CHILDREN=300, and set Instances to 300, but one drawback with this thought, each PHP process will create it own shared memory for opcode cache.
And I think you don't really need to set Max connections to 300, 50 is more than enough for most web sites. :-)