Why is the list text so close to the top line of the cell in some lists? I know it's a problem with the parskip package.
I can solve this by adding this strut in every cell before the text
\newcommand{\mystrut}{\rule{0pt}{\baselineskip}}
I think I can't add the strut before the column in the tabular environment since I don't want every column to be the same size, but adding the strut in every cell feels wrong and I do need the parskip package. Is there other way to do this.
\documentclass[a4paper]{article}
%% parskip en las minipages%
\usepackage[parfill]{parskip}
% %% TABLAS. AJUSTAR EL TEXTO A LA CELDA
\usepackage{tabularx}
\usepackage{multirow}
\usepackage{pifont}
\renewcommand{\tabularxcolumn}[1]{>{\centering\arraybackslash}m{#1}}
\newcolumntype{L}{>{\raggedright\arraybackslash}X}%
\newcolumntype{R}{>{\raggedleft\arraybackslash}X}%
\begin{document}
\begin{table}[H]
\centering
\begin{tabularx}{1.3\linewidth}{| m{3.5cm} | X | X |}
\hline
\texttt{Material} & \texttt{Ventajas} & \texttt{Inconvenientes}\\\hline
INVAR & \begin{dinglist}{51}
\item Bajo CTE
\item Alta conductividad térmica
\item Durabilidad
\end{dinglist}& \begin{dinglist}{55}
\item Altísimo coste
\item Altos tiempos de retorno
\item Aumento de los costes de fabricación
\end{dinglist}\\\hline
Acero &\begin{dinglist}{51}
\item Alta conductividad térmica
\item Durabilidad
\end{dinglist} & \begin{dinglist}{55}
\item Mayor CTE que el CFRP
\item Alabeo de las piezas fabricadas
\item Alto coste de fabricación
\end{dinglist} \\\hline
\end{tabularx}
\end{table}
\end{document}

parskippackage never solves problems; it adds some. Using a nonzero parskip is a device frowned upon by typographers. – egreg Sep 12 '14 at 16:41