\documentclass[russian]{report}
\usepackage{array}

\begin{document}

% use of \tabularnewline
\begin{tabular}{|>{\centering}p{0.08\paperwidth}|>{\centering}b{0.08\paperwidth}|>{\centering}m{0.08\paperwidth}|}
\hline
A1 \\ aa A1 & B1 \\ aa B1 & C1 \\ aa C1 \tabularnewline
\hline
A1 & B1 & C1 \tabularnewline
\hline
A2 & B2 & C2 \tabularnewline
\hline
\end{tabular}

% old style row endings
\begin{tabular}{|c|c|c|}
A \\ & B \\ & C \\
A & B & C \\
A & B & C
\end{tabular}
\begin{tabular}{|c|c|c|}
A & B & C \\
A & B & C \\
\end{tabular}

% use of \tabularnewline
\begin{longtable}{|>{\centering}p{0.08\paperwidth}|>{\centering}b{0.08\paperwidth}|>{\centering}m{0.08\paperwidth}|}
\hline
A1 \\ aa A1 & B1 \\ aa B1 & C1 \\ aa C1 \tabularnewline
\hline
A1 & B1 & C1 \tabularnewline
\hline
A2 & B2 & C2 \tabularnewline
\hline
\end{longtable}

% old style row endings
\begin{longtable}{|c|c|c|}
A \\ & B \\ & C \\
A & B & C \\
A & B & C
\end{longtable}
\begin{longtable}{|c|c|c|}
A & B & C \\
A & B & C \\
\end{longtable}

\end{document}