The phrase "tiny dab" means adding a very small amount of something.
Sentences with «tiny dab»
Secure the seam binding with tiny dabs of glue. (styleathome.com)
We stick with pasta dishes for the girls containing just pasta, some vegetable and a teeny tiny dab of butter (the girls hate butter but I use it sparingly) (mommyniri.com)
With the final layer of paint, she builds forms using a type of neo-Pointillism: thousands of tiny dabs create a palpable Braille - like surface across her paintings. (massart.edu)