The traditional Russian New Year's Eve salad made with diced vegetables and ham is Olivier salad.
Also called Russian salad or Stolichny salad in some contexts, Olivier salad is built from diced boiled vegetables—commonly potatoes and carrots—mixed with pickles, peas, eggs, meat, and mayonnaise. Ham is one possible meat ingredient, though sausage, chicken, or other meats are also common.
The dish is generally attributed to Lucien Olivier, a Belgian chef who created an elaborate salad at the Hermitage restaurant in Moscow in the 19th century. Over time, expensive ingredients from the original version were replaced with more accessible household foods.
In Russia and other post-Soviet countries, Olivier is strongly associated with Novy God, the New Year's celebration. A frequent mix-up is Shuba, or herring under a fur coat: that is a different layered beet-and-herring salad, not another name for Olivier. Vinegret is also distinct and is typically a vegetable salad without the same mayonnaise-based mixture.