50 people on a single access point isn't recommended, especially if they're allowed to bring their own devices like phones, tablets, smart watches, other smart devices etc.
I'd recommend at minimum a Unifi Dream Router $199 and atleast 1 additional wired access point, wired to the built in switch and placed 50-100 feet away from the router.
It's also important to what a consumer calls a "Router" is actually 3 individual products that are smushed into these consumer products. That is a Router, Switch, and Wireless Access Point.
If this is a truly professional office situation, you should deploy a professional setup that can be configured to specifically protect your internal assets and products.