I just bought an oval dining room table, and now find there are very few oval tablecloths out there. Is it proper to use an oblong tablecloth on an oval table?

It depends on size of tablecloth in relation to oval table.

U can have a tablecloth made to fit if u don't like the way it looks.

Chuck

Pretty much anything is proper now. If YOU like the way it looks and fits (no wrinkles) to tip glasses on, then go for it.:)