Mein "minimal"Beispiel. Es können zwar ein paar usepackage weg, die verkürzen dann allerdings hline so das die Tabelle nur zu 3/4 horizontale Linien hat.
\documentclass[11pt,a4paper]{article} % Use A4 paper with a 11pt font size - different
\usepackage{marginnote} % Required for margin notes
\usepackage{wallpaper} % Required to set each page to have a header-logo
\usepackage[left=2.0cm,right=1.0cm,top=1.8cm,bottom=1.8cm,marginparwidth=3.4cm]{geometry} % Adjust page margins
\usepackage{amsmath} % Required for equation customization
\usepackage{amssymb} % Required to include mathematical symbols
\usepackage{xcolor} % Required to specify colors by name
\usepackage{epstopdf} % Required to include logo
\usepackage{fancyhdr} % Required to customize headers
\usepackage[colorlinks=false, pdfborder={0 0 0}]{hyperref} % this is needed for forms and links within the text
\usepackage[latin1]{inputenc} % this is needed for german umlauts
\usepackage[T1]{fontenc} % this is needed for german umlauts
\usepackage{pgfplots}
\usepackage{tabularx}
\usepackage{fixltx2e}
\usepackage{selinput}
\usepackage{graphicx}
\setlength{\headheight}{70pt} % Increase the size of the header to accommodate meta-information
\pagestyle{fancy}\fancyhf{} % Use the custom header specified below
\renewcommand{\headrulewidth}{0pt} % Remove the default horizontal rule under the header
\setlength{\parindent}{0cm} % Remove paragraph indentation
\newcommand{\tab}{\hspace*{2em}} % Defines a new command for some horizontal space
\newcommand\BackgroundStructure{ % Command to specify the background of each page
\setlength{\unitlength}{1mm} % Set the unit length to millimeters
\put(153, 270){\includegraphics[height=15mm,keepaspectratio]{logo.eps}} % Logo box - maximum height/width:
}
\newcommand{\underlineLength}{4}
\newcommand{\tfw}{10mm}
%“running in backwards compatibility mode” Compiler Warning
\pgfplotsset{compat=newest,compat/show suggested version=false}
% HEADER INFORMATION
\fancyhead[L]{\begin{tabular}{l r l r} % The header is a table with 4 columns
\textbf{Firma:} & $\rule{\underlineLength cm}{0.15mm}$ & \textbf{Name:} & $\rule{\underlineLength cm}{0.15mm}$ \\ %
\textbf{Straße:} & $\rule{\underlineLength cm}{0.15mm}$ & \textbf{Vorname} & $\rule{\underlineLength cm}{0.15mm}$ \\ %
\textbf{PLZ/Ort:} & $\rule{\underlineLength cm}{0.15mm}$ & \textbf{Tel.:} & $\rule{\underlineLength cm}{0.15mm}$ \\ %
\textbf{Land:} & $\rule{\underlineLength cm}{0.15mm}$ & \textbf{E-Mail:} & $\rule{\underlineLength cm}{0.15mm}$ \\
\end{tabular}}
\begin{document}
\begin{Form}
\noindent\makebox[\linewidth]{\rule{\paperwidth}{0.4pt}} % Horizontal Line
\AddToShipoutPicture{\BackgroundStructure} % Set the background of each page to that specified above in the header information section
\section{Technische Daten}
\begin{tabularx}{\textwidth}{|llr|llc|}\hline
Induktivität bei Nennstrom L\textsubscript{N}&\TextField[name=IN,width=\tfw]{}& $\mu$H&Nennstrom:&\TextField[name=Nennstrom,width=\tfw]{}&A\textsubscript{eff}\\\hline
\end{tabularx}
\end{Form}
\end{document}
