That doesnt involve any PHP code at all...looks like you're spidering your URLs which end in a php script (makes no difference)
First line will run wget on the 5th minute of every hour. Second like will run on the 10th minute of every hour and the thrid will run every hour at the begining of the hour.
Hopefully this helps you out
PS: You may or may not need to put the full path to wget. You should be able to find the absolute path by running "which wget" without the quotes