Thanks for your request. You can try inserting a Bookmark in a table, which you would like to find. Then you can use the following code to find a table:
Document doc = new Document("in.doc");
// Get bookmark
Bookmark bk = doc.Range.Bookmarks["bookmark"];
if (bk != null)
{
// Get table, where bookmark is located.
Node table = bk.BookmarkStart.GetAncestor(NodeType.Table);
if (table != null)
// Work with table.
}