Update basic.html

You should never have an empty table.  Nesting two empty tables together will work, height must always be greater than 3 and any additional height should be defined with cellpadding as much as possible (e.g. spacer of 14px would be cellpadding=5 height=4; spacer of 25px would be cellpadding=11 height=3) .. height always 3 or greater, but majority defined on padding because cellpadding is more reliable.