Translation:We are putting the bottles into the big box.
You use "kłaść" + "na" + Locative or Accusative when you put something on a surface. Locative focuses on when it ends up, Accusative focuses on the movement of 'putting', the difference is so slight that we can safely say they're the same.
You use "wkładać" + "do" + Genitive when you put something inside something.
For rather rare example, I can perhaps imagine using "kłaść" + "w" + Locative if I let's say put a toy at the bottom of a box, so in a way it's both putting it on a surface, and inside something. It seems safer to just treat it as 'inside something; as above.
For "wkładać" + "w" + Accusative I can only imagine putting a box inside another, slightly bigger box and saying "wkładam pudełko w pudełko".