How to share wired Internet access with WiFi device


TS Booster
I've a wired network at home like this:
ADSL Router
Dlink Switcher
|      |     |
PC1   PC2   PC3
I'm going to buy a new tablet (ASUS MeMO Pad Smart 10), which supports internet through wifi. I was wondering how can I share the internet access with the new device? What new devices should I buy and what changes are required to my network setup?

Thanks in advance.