Please can you explain why no "un" for asiento

Question

"Espero que nos den asiento en una mesa cerca de la ventana"Please can you explain why here, 'I hope that the give us SEAT on a table close to the window'   Is this a nuance in Spanish?Thanks

Answer

Hola Paul
It wouldn't be wrong to use the article "que nos den un asiento en una mesa..." but we drop it because we are using the word "asiento" with a very general meaning, as in "any seat"; it's also pretty much a set expression used without the article, for example, you could hear from the waiter as you enter a restaurant something like "tomen asiento por favor" (no article here either), meaning "please, seat/take a seat".
Another similar example where we drop the article could be for example:

¿Vamos a tomar café?
Shall we go for a coffee?

We are thinking about coffee in general, not a specific coffee.
Saludos
Inma