Paja

[ROBINDESBOIS]

Cuando habla/escribe mete mucha paja (= mucha basura, no es importante, da muchas vueltas a un tema y no dice nada) In English?

[Rusty]

yakety yak
gobbeldygook
mumbojumbo / mumbo jumbo
gibberish (but usually applied to something unintelligible)

talking for talking's sake
talking just to hear one's (own) voice

[Luz]

puede ser : to pad out? en el sentido de meter mucha paja en una redacción pare rellenar folios.

Talvez los nativos ingleses puedan confirmarlo

[ROBINDESBOIS]

Thanks Rusty is that for writing too or only verbal?

[Rusty]

Both written and verbal speech can be filled with gobbeldygook.

Padding (out) (or waffling) also works. We also say that someone's words were all/mostly fluff.

[Ambarina]

The one I use most is waffle in this context.
Most of what he said/wrote was sheer waffle.