In Medieval Times, People were called Lance a Lot.

Humourless types might like to point out that the spelling Lancelot only dates to 1170 and the writing of Chrétien de Troyes. 

So the name was not used a lot in medieval times, and in any case the name is French and hence 'lot' would be pronounced 'low'. 

However, Chrétien gives so little detail of Lancelot's background that it has been suggested the Lancelot myth was already known to his readers before being incorporated into "The Matter of Britain." A popular view is a (perhaps reverse) Euhemerism of the Celtic god Lugh Lonbemnech.

I bet you always wanted to know that.