I am trying to find a large wooden tray approx. 33"x33" which will sit
on a sofa puffet or whatever you call them. This will make it into a
table-somehow.Can you help,please? Thank you.

Hi Wilma,
I didn't see any big enough trays during a quick web search, but there
are a couple of alternatives.
Firstly, card tables are about the right size. You could cosider
purchasing just the top of a card table, then decorating it to suit.
Here is a webiste that may be able to sell you just the top.
http://www.smallfoldingtables.com/card_tables.html

Another alternative is purchasing a coffee table and sawing off the
legs. See, for example, the following.
http://www.ikea-usa.com/product_presentation/show.asp?productnumber=95157109&type=ART&id=5999,472

Also, Ikea sells tabletops and legs separately, so you may find
exactly what you need without having to do any alterations. (They only
had one example online, but do actually have more available - you'd
have to ask.)
http://www.ikea-usa.com/product_presentation/subcat.asp?id=431,433

Good luck in your search!
alex_p

Another alternative is to have a tray custom made. A quick google
search for "custom furniture" came up with lots of potential sites.

://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22custom+furniture%22