First, Welcome to the boards.
If you want to have tablemates or not is a decision only you can make. But for us, the traditional cruise dining (being seated with others) is one of the best parts of cruising. We have made great friends with some of our tablemates that
DCL has just randomly picked for us and others we've enjoyed talking with through the cruise but didn't have long connections with. We've also had others that were not so great but those we think of as theater and sit at dinner and just enjoy the show! Usually they do try to seat you with like travelers so if you are adults only, you'd most like be seated with only adults. I do think they try to match ages as best they can as well. Don't know what their formula is but we've found it's a good match more often that not.
If you think it is something you might enjoy, go for it. If you find it isn't for you or you happen to get tablemates that really would disrupt the enjoyment of your vacation, you would still have options -- you can ask the Head Server to reseat you and if you're really uncomfortable with running into them ask if you can be reseated at the opposite dining time or in another rotation; or you can use alternative dining for your meals -- Cabanas for at least the 2nd and 3rd nights or the Quick Service or Room Service.