Tables Generator lets you create tables for LaTeX or HTML documents

“Entering tables in LaTeX documents can be burdensome because of the necessary formatting directives. For this purpose we created this online generator which (hopefully) will allow you to generate LaTeX code you can just copy & paste into your document’s source. Our editor is close to WYSIWYG (What You See Is What You Got) principle, i.e. the table displayed in the editor should resemble the final table.
[…]
Creating tables in HTML seems to be somewhat easier than in LaTeX, the syntax is simpler but more verbose. There are countless tools available which allow you to create tables in HTML format, nevertheless if you just need a quick and simple tool you may use the generator on our site. It supports features like cells merging, text align and some simple styling.”

I found this site the other day while trying to typset a table for a math test in LaTeX in which I needed merged cells across several rows and columns. Worked like a charm!