What is the maximum RAM capacity of Lenovo Yoga 460 laptop. It shows 8 GB RAM WITH ONE SLOT EMPTY?

Max memory 8gb. Looks like you are already maxxed out. Surprised a bit though so perhaps you should check the lenovo site for your country as you didn't say which country you purchased it.

Is this what you have?

http://www.crucial.com/...d-yoga-460

if it is… You can add 1 - 8 gig stick…( laptop maxes out at 16 gig )

See maker's website for your particular model under specifications