Learn Spanish (Latin America): Ese kiosco era un lugar ruidoso.

Era is the imperfect tense of the irregular verb ser (to be). We use the imperfect here because we are describing a characteristic of the kiosk in the past. We are setting a scene rather than talking about an action that had a clear beginning and end.

Why is it ese kiosco and not eso kiosco?

Ese is the masculine singular word for that when it comes directly before a noun. You use eso when you are talking about an abstract idea or an unidentified object, but never right next to a noun.

How is the word ruidoso formed?

It comes from the noun ruido (noise). Adding the ending -oso turns it into an adjective meaning noisy. It works a lot like adding -y or -ous to the end of a word in English.

I have also seen this word spelled quiosco. Is kiosco different?

No, they are the exact same word! Kiosco and quiosco are just two accepted ways to spell it. Both mean a small stand or kiosk, and both are completely correct to use in Spanish.