If you have a switch with 3 or fewer cases, use if/else. If you have a switch with more cases, a hash table is going to wind up with far less code, and set you up for polymorphism later if you decide you need to go that route.
I disagree that hash tables will end up with less code; the dispatch mechanism for a hash table will be significantly longer than a switch, and the compiler can create a hash table for dispatch (using e.g. a perfect hash function). A switch statement will both be faster and easier to understand and read than storing lambdas in a hash table.
For pure readability, languages with good support for hash literals and lambdas may have the edge, but they'll also encourage dynamism that will hurt both simplicity and performance.