You need to cancel the sale and relist with appropriate postsge - Parcelforce might take such a large item.
Personally, i would sell it as 'collection only' as the postage cost will be high in relation to the cost of the table.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)