Does a blockchain need a distributed hash table? In this question on StackOverflow, the OP is asking if there is a difference between distributed hash tables and blockchain. The answer to that question seems to indicate that there is no point of overlap between the two as they are for completely different purposes. However, I would like to clarify this point. 

To the best of my knowledge, blockchain is a peer-to-peer implementation, which means that the entire blockchain is stored in every peer. However, if there is a need to broadcast consensus of a particular transaction, there is still a need to look up the other peers in some kind of table of addresses. Am I correct? (My underlying question is: In a blockchain, would all nodes or peers get the information about successful transactions simultaneously? It doesn't seem likely to me, and I'm trying to understand the protocol for doing this broadcast in a simultaneous, or near simultaneous manner).
No. Peer discovery does not use a distributed hash table and cannot use a DHT. Once you are connected to the network, there is no need for you to find more peers to connect to (and most nodes have a limit of 8 anyways as that is Core's outbound connection limit).

The broadcasting of transactions and blocks themselves does not rely on the broadcaster to find all peers and send the data to each peer. Rather it simply sends the transaction or block to the peers it is connected to, and then those peers check the block and transaction, and if it is valid, they will send the block or transaction to their peers, and so on and so forth.