Some chicken soup that had been poured into a bowl several minutes prior but was still hot splashed on a milchig knife and plastic milchig cutting board. It was a small amount and less than a 60th. Can the knife and cutting board still be used for dairy?

ב"ה The bowl which was poured into is considered a "kli sheni"- a second vessel, from which this spilled onto the knife and cutting board which are considered a "kli shlishi". Therefore, we can be lenient because it is not really considered that it absorbed the chicken soup. However, since the chicken soup was hot you should pour boiling water over the knife and cutting board and then you may use it as usual. (שו"ע יור"ד קה:ב, או"ח סי' תנא, שע"צ ס"ק י. וראה ספר הגעלת כלים פרק ה) All the best