Starcrawlers is a nice and relaxing RPG with a ton of humour too. Except for some evasion of security cameras and navigating some traps the game is completely turn based. You can save any time, it's not too complex and if a story mission proves too hard you can grind a few levels with generated missions (except in the end when you reach the level cap).

Well, how about this:
https://www.gog.com/game/wartile

I totally forgot this one, who is awesome (I wonder how I could have forget to tell you about it XD) :
https://www.gog.com/game/field_of_glory_ii
A turn based strategy game, and it has a very strong tabletop feeling ! It's balanced, very interesting to play, and the AI is good !
I very strongly recommend you to take a look at it :)
(and it's currently on sale ;))

The default party is plenty sufficient to get you through the game. Tips/advice for how to spend skill points are easily available if you make a post in the MM subforum (or just browse some of the threads there, since character/party discussion happens periodically).

Tabletop Simulator

Rezrog

This is actually true in many of the other games in the series. The biggest exceptions I can think of are as follows:

MM2: The Cleric in the party is slow, and therefore doesn't get a chance to cast a spell like Bless before he constantly has to heal. Also, the gender balance is off; you should either make a female Knight or make both your Paladin and Cleric female. (There are some enemies that are immune to physical attacks from characters of one sex (does this make any sense at all?), and Personality can only be boosted for one sex at a time.)

MM3: The default party has no Druid or Ranger, meaning no access to Walk on Water. Given the fact that the world map consists of a bunch of islands (just look at the subtitle of the game!), this spell is kind of important. (I recommend replacing one of the front line characters with a Ranger.)

Swords of Xeen: If you are going to play this, the default party is rather poor; it includes both a Robber and a Ninja, and you don't want either in this game. (Also, Swords of Xeen is *not* a good introduction to the series; at least play World of Xeen first, and even then be aware that SoX has a bunch of scripting bugs and balance issues that may be severe enough to make the game not fun for many players.)

(World of Xeen's default party, while not 100% optimal, is definitely sufficient to get through the game and have fun with it.)

Avernum. And the games have free demos anyway.

Since I've already given some more realistic recommendations, there is one other game that, to my understanding, would fit the "tabletob" feeling. Only problem is that it's a semi-old console game (PlayStation 2) that, to my knowledge, is not (legally) available digitally, so it might not be so easy to get.

That game is Unlimited SaGa. I haven't played that game (though I have a copy around somewhere), but my understanding is that the game has a table-top feel, with movement around something like a board and various slot reels acting like dice (though you apparently have some control over it).

On the other hand, I don't know how relaxing this game is, as it is rather famous for having obscure mechanics that you would need to figure out or look up ("How do I open a treasure chest?" is a common question players have). The SaGa series is rather unorthodox as a whole, but Unlimited SaGa is rather unorthodox even by SaGa standards. It might be worth looking for a different SaGa game first.

One game I keep coming back to and might just fit the description - Etherlords II.