Question

why we are able to sip hot tea or milk faster from a saucer rather than a cup

Answer 1

We are able to sip hot tea or milk faster from a saucer rather than a cup because surface area of saucer is more than surface area of a cup.
Evaporation is a surface phenomenon, so evaporation will take place faster in saucer instead of a cup that's why we are able to sip hot tea or milk faster from saucer.

Answer 2

This is because saucer had more area than cup and it rate of evaporation and diffusion is also high