Avoid line break between html elements

CSS for that td: white-space: nowrap; should solve it.

There are several ways to prevent line breaks in content. Using   is one way, and works fine between words, but using it between an empty element and some text does not have a well-defined effect. The same would apply to the more logical and more accessible approach where you use an image for an icon.

The most robust alternative is to use nobr markup, which is nonstandard but universally supported and works even when CSS is disabled:

<td><nobr><i class="flag-bfh-ES"></i> +34 666 66 66 66</nobr></td>

(You can, but need not, use   instead of spaces in this case.)

Another way is the nowrap attribute (deprecated/obsolete, but still working fine, except for some rare quirks):

<td nowrap><i class="flag-bfh-ES"></i> +34 666 66 66 66</td>

Then there’s the CSS way, which works in CSS enabled browsers and needs a bit more code:

<style>
.nobr { white-space: nowrap }
</style>
...
<td class=nobr><i class="flag-bfh-ES"></i> +34 666 66 66 66</td>