, i need to make up 10-12mm with adhesive can i spot my tiles rather than spread the adhesive

[Kevbos]

Don't be pushing tolerances of adhesives with a weak tile .get walls made flat

 

[One Day]

Spot fixing marble runs a big risk of domino spots - and also cracking, as the adhesive spots set at different rates.
A big no no unless those spots add up to at least 90% coverage when bedded.

 

[Dan]

Use another method to bring the walls out. Don't spot fix.

You'll also need to back skim the marble. And if they are light in colour perhaps use a white adhesive.

 

[Qwerty]

Glue & mechanically fix tile backer boards to the walls. This will take up the room you need and provide a solid strong substrate on which to fix your stone using a full bed of adhesive. Marble is not they type of material to fix incorrectly.