Use the \twocolumn
format, then you can use the package supertabular
\documentclass[11pt,a4paper]{article}
\usepackage{supertabular}
\begin{document}
\twocolumn
\tablehead{Header of first column & Header of second column \\}
\begin{supertabular}{ccc}
Table cell 1, 1 & Table cell 1, 2 \\
Table cell 2, 1 & Table cell 2, 2 \\
Table cell 1, 1 & Table cell 1, 2 \\
...
...
\end{supertabular}
\end{document}
together with the package multicols
you can only use the tabbing
environment.
The big problem with your idea is the way, LaTeX is building the page.
If you have two colums on the page, LaTeX has to calculate it. You want to end the "two column mode", change to one column to add your footnote or footnotes. There are a lot of things influencing the result, like the length of the paragraphs, the length of the footnotes, that causes an changing of the length of the column etc. That is not easy to calculate!
If you argue but there is the possibilty to have an abstract in one column please see that the situation is an other there. It is much more easier to insert an box for the complete textwidth at the beginning than at the end.
My english is not so good, so please have a look for example to this question and see the accepted answer. perhaps it is today possible, to do the recalculation with expl3
as mentiond by Frank Mittelbach, but I can't do that.
So I suggest you to use the following MWE to get hyphenated urls placed in the column they belong to:
\documentclass[10pt,conference,a4paper,twocolumn]{IEEEtran}
\usepackage{showframe} % <======================== shows the typing area
\usepackage{blindtext} % <========================= to create blind text
\usepackage[hyphens]{url} % <================ allows hyphenating of urls
\usepackage[colorlinks,urlcolor=blue]{hyperref}
\begin{document}
\Blindtext
Some random text\footnote{\url{
http://ec.europa.eu/digital-agenda/interoperability-standardisation-connecting-ehealth-services}}
\Blindtext
Some random text\footnote{\url{
http://ec.europa.eu/digital-agenda/interoperability-standardisation-connecting-ehealth-services}}
\Blindtext
\end{document}
and the resulting first page:
showing clickable blue urls.
Best Answer
Please always supply a test document.
This is easy if you are prepared to add some space manually in the second column.
The wide text is just placed naturally in the first column together with some negative space so that it overprints the second column. then you just need to add a
\vspace
to leave a gap.