Yes if the data is tabular then the most semantic element to use is a table and I suspect that a table is what you probably need here.
If the data isn't tabular (and only you know that at the moment) then yes you can float columns to arrange your layout as you want but I'd need to know the structure and look you are going for.
From the sounds of it though I think a table is what you should be using here
I think I'll go with the float class because this grid could expand in time as my customer keep adding some stuff and I think that it will be more flexible.
I just found a site that seems to use that trick so I'll give it a try before send more posts,
Bookmarks