Constructing Reed-Solomon (RS) codes that can correct insertion and deletion (ins-del) errors has been the focus of several recent studies. However, efficient decoding algorithms for such codes have received less attention and remain a significant open problem. In this work, we take a first step toward addressing this problem by designing a decoding algorithm for the case of $2$-dimensional RS codes that can correct deletions up to the half-Singleton bound and is optimal in terms of field operations.