Question: were you in merchant's row or off somewhere else?
The reason I ask is that if you were in with the other merchants, a table, while helpful, is not necessary. This is especially the case in a situation like yours where you have just a few items. Also, in some cultures during the medieval period, it was the norm to spread a cloth on the ground instead of having a table.
AS to the rest of your list, definately have some kind of sign. I know a few merchants who don't and I can never remember the name of their business. Below is a pic of my booth from a Northshield event in 2010. The banner is my sign.
Having a good amount of merchandise is definantely(SP?)a good idea, but if you think about it, you sold 75% of the stock you took. That's really good! Granted, more stuff may have lead to more sales. But then again, that might have been all you sold that day. I've gone to events where I've sold five things out of 150. Others where I've sold 40 out of 60. One just never knows how things will go at an event. But more is usually better.
And I agree, business cards are a good idea. sales may not come right away from them, but someone may be sitting at home one day an find the card ans say "OOOOhhh, That's right I need to contact X and get (insert) from them."
Hopefully your fun experience will keep you merchanting. I don't always sell much, but I get to meet lots of people and my friends always know where to find me.