Why are silyl chlorides more readily hydrolysed than alkyl chlorides?
Using $\ce{CCl4}$ and $\ce{SiCl4}$ as the basis for comparison, there are several reasons.


The greater electronegativity difference between Si and Cl leads to a larger $\delta^+$ on silicon, making it more electrophilic and susceptible to attack by water.
Larger size of Si means that there is less steric hindrance towards the approach of water.
It is possible that the hydrolysis of $\ce{SiCl4}$ proceeds via an alternative, faster pathway that involves a five-coordinate intermediate (as opposed to $\ce{CCl4}$, in which five-coordinate carbon does not occur).