Here is a mock-up that duplicates one of the tables listed in your link. I'm sure you could modify this to suit based on your requirements:

\documentclass{article}
\usepackage{booktabs}% http://ctan.org/pkg/booktabs
\usepackage{colortbl}% http://ctan.org/pkg/colortbl
\usepackage{xcolor}% http://ctan.org/pkg/xcolor
\newcommand{\topheading}[1]{\multicolumn{2}{c}{\textsf{\textbf{#1}}}}%
\newcommand{\midheading}[1]{\multicolumn{2}{l}{\cellcolor{black!5}\textsf{#1}}}%
\begin{document}
\begin{tabular}{@{\quad}l@{\quad}l}
\topheading{Indicative} \\
\specialrule{\heavyrulewidth}{\aboverulesep}{0pt}\arrayrulecolor{black!5}%
\specialrule{\lightrulewidth}{0pt}{0pt}\arrayrulecolor{black}
\midheading{Present} \\
bebo & bebemos \\
bebes & beb\'eis \\
bebe & beben \\[\jot]
\midheading{Preterit} \\
beb\'{\i} & bebimos \\
bebiste & bebisteis \\
bebi\'o & bebieron \\[\jot]
\midheading{Imperfect} \\
beb\'{\i}a & beb\'{\i}amos \\
beb\'{\i}as & beb\'{\i}ais \\
beb\'{\i}a & beb\'{\i}an \\[\jot]
\midheading{Conditional} \\
beber\'{\i}a & beber\'{\i}amos \\
beber\'{\i}as & beber\'{\i}ais \\
beber\'{\i}a & beber\'{\i}an \\[\jot]
\midheading{Future} \\
beber\'e & beberemos \\
beber\'as & beber\'eis \\
beber\'a & beber\'an \\
\bottomrule
\end{tabular}
\end{document}
colortbl provides some row colour, while xcolor provides the colour interface (for example, black!5 is 5% black). booktabs provides the modified tabular layout, including the use of modified rules via \specialrule{<width>}{<above sep>}{<below sep>}.
Spacing between tense blocks is given by \\[\jot] which leaves an additional 3pt gap.
I've added an indent on the left of \quad (given by the first @{\quad} in the tabular column specification), as well as a space between the words of \quad (given by the second @{\quad} in the column specification). Main header is set via \topheading{<stuff>} while the tense headers are set via \midheading{<stuff>}. Since the tabular format is rigid - 2 columns - the commands conform to this setup by necessarily spreading its contents over 2 columns (via \multicolumn{2}{l}{...}). Again, this is just one way of doing it; there are plenty of other ways of doing it.
\conjugate{beber}or\conjugate{comer}for any regular -er verb you want, and it'll produce the entire chart for you. – JohnJamesSmith Jan 23 '12 at 3:02\'eevery time you mean "é". – JohnJamesSmith Jan 23 '12 at 3:03