Multicols

\documentclass[12pt,a4paper]{article}

\usepackage[T1]{fontenc}                            % Vise norske tegn.
\usepackage[norsk]{babel}                           % Tilpasning til norsk.
\usepackage[utf8]{inputenc}                     % For å kunne skrive norske tegn.
\usepackage{booktabs}
\usepackage{lipsum}
\usepackage{enumitem}
\usepackage{multicol}
\usepackage{ragged2e}

\SetEnumitemKey{threecol}{
itemsep=1\itemsep,
parsep=1\parsep,
before=\raggedcolumns\begin{multicols}{3}\RaggedRight,
after=\end{multicols}}

\begin{document}

    \begin{enumerate}[threecol]

    \item[\bf Januar]    SDS-PAGE
    \item[\bf Februar]   Western Blot
    \item[\bf Mars]      Antibody affinity
    \item[\bf April]     Differential
    \item[\bf Mai]       Immunoprecipi
    \item[\bf Juni]      Genome sequencing
    \item[\bf Juli]      Genomic analysis
    \item[\bf August]    Mass spec
    \item[\bf September] Bioinformatics
    \item[\bf Oktober]
    \item[\bf November]  Numerical analysis
    \item[\bf Desember]  Software design

    \end{enumerate}

    \begin{enumerate}[threecol,label = \bfseries \arabic*] \itemsep -2pt

    \item SDS-PAGE
    \item Western Blot
    \item Antibody affinity chromatography
    \item Differential and Density gradient centrifugation
    \item Immunoprecipi\-tation
    \item Genome sequencing
    \item Genomic analysis (copy number, SNP-detection, IGV, samtools, picard, etc.)
    \item Mass spec
    \item Bioinformatics
    \item Numerical analysis
    \item Software design
    \item High, medium, and low level programming design
    \item Linear algebra
    \item Graph theory
    \item Regression analysis

    \end{enumerate}

\end{document}