It is a dowry for the King and Guinevere. In the original story Guinevere is king Leodagrance's daughter and so when arthur and her get married the table was given as a gift.
In Merlin, Gwen (Guinevere) is a servant for the Lady Morgana, (King Uthers ward). Even though she is still a servant, she marries Arthur and Becomes the Queen of Camelot.
I It is a dowry to King Arthur and Guinevere, his wife. When they married Gwen's Father King Leodegrance gave the round table to them. In the version I know, (Here we go) Guinevere was a servant to the Lady Morganana, Uther's Ward, they fell in love but it is a disgrace for A king to marry a servant and uther forbid it, oh plus Gwen's father was a blacksmith, and died anyway so it's not like he could have given it to them, Arthur had found the round table in an abandoned castle. They did end up getting married but a whole load of horrible stuff happened and yeah, I can't spoil much, its pretty important. Gahh! I think I told you way to much already! XD
Gold, copper, silver, bronze metals were known to Indus Valley Civilization but not iron. The Indus valley people or Harappan people not discovered iron
