Custom Hashset in Java
Improving names:


Your class has 2 size variables, which looks kinda strange. Better to rename this private static one to something like INITIAL_CAPACITY (or DEFAULT_INITIAL_CAPACITY, if you have plans adding constructor with initialCapacity parameter), because size = how many elements are stored, but this variable denotes initial array length.
method hash in reality returns bucket index for given element, thus, should be renamed. For example, to indexFor or bucketIndex. 


Other:


in Entry - next is not parameterized (as well as its getter and setter).