I am planning to make a dining table, dimensions 2000mm x 960mm x 40mm, in
either beech or oak.

The company selling me the timber suggests this would need 9 legs, which
is ridiculous. (I don't think I've ever seen a table with 9 legs before.)
It's a crucial part of the plan that the table have only 4 legs. But I like
this company's tabletops.

What are my options? Bolt two lengths of steel tube to the underside? Or
would I need a rectangle? Would it be possible to use timber? I realise it
would have to be bulkier. What would people recommend?

Thanks in advance!

Harry