Board Game Arena

Where do I go to find out what the Table Configuration options in a given game do?

Table configuration options are tied to variations in the rules. For example, Cinco with 6 players can be played as 2 teams of 3 each, or 3 teams of 2 each. Therefore, this is one of the configuration options. A careful reading of the rules should explain what each option does.

Additionally, there are options of how turns are actually played: Realtime vs Turn-based, for example. This affects how much time each player has to make a move before incurring a slow play penalty.

Was there a particular option that needed explanation?

I can't figure out what Old Mine and New Mine do in Saboteur.

I think a tooltip next to the options that provides further detail wouldn't be the worst thing in the world.

Strange -- a version of the Italian wiki page (written in English) had the explanation, but not the English wiki page. This has been corrected. When the rules summary page updates, it should show up.

But, until then...
Two variants are about gold sharing:
Old Mine: the old mine was not as packed with gold... sometimes all you got for your digging was worthless stones. In this variant, some 'Gold' cards do not yield any gold nuggets (among the 28 'Gold' cards, 4 are worth three nuggets, 8 are worth two nuggets, 10 are worth one nugget and 6 are worthless). So it is definitely best to get first to the treasure in order to be sure not to leave empty-handed!
New mine: the new mine is more even to each gold digger. Instead of distributing as many 'Gold' cards as the number of players - which benefits most to the gold digger that gets first to the treasure as he often gets two 'Gold' cards - it distributes as many 'Gold' cards as the number of gold diggers in play. Therefore, each gold digger will get only one 'Gold' card (however, it is still best to be first go get to the treasure in order to get a card of higher value!)
Two variants are about gameplay:
Competitive: the gold diggers who have a 'Sabotage' card (broken pickaxe, lamp or trolley) laid in front of them at the end of a round, do not receive a 'Gold' card when their team wins the round. The 'Gold' cards are distributed between the gold diggers who have no broken tool (saboteurs are not affected by this rule). Therefore, with this variant it can be interesting to sabotage some of your fellow gold diggers... but not too often, so as not to make your team lose!
Selfish dwarf: one of the gold diggers will get a red jacket. This gold digger is a selfish dwarf: he can only win if he manages to complete the connection to the treasure himself. In this case, he gets four gold nuggets while the other players get nothing at all. If another gold digger completes the connection, the selfish dwarf takes no part in the treasure sharing (which is done with as many 'Gold' cards as the number of players, selfish dwarf excluded)