The Google Chrome team has just rolled out Chrome 67 across all platforms, which brings in a slew of changes behind the scenes, but the big change that users are going to notice is that Chrome is using even more RAM than usual. In fact, Chrome is going to be using about 10-percent more RAM with this update. This is because of the fixes that the Chrome team needed to include for Meltdown and Spectre. So while your internet browsing is going to be safe from these exploits, you're going to be using more RAM for your browsing.
The Chrome blog has announced the update and detailed what's new here. Google's software engineer, Charlie Reis spoke about Site Isolation which is used to protect Chrome from these exploits, noting that "Site Isolation does cause Chrome to create more renderer processes, which comes with performance tradeoffs. There is about a 10-13 percent total memory overhead in real workloads due to the larger number of processes." Now that is a pretty big chunk of RAM, and Chrome already uses a big chunk of RAM. Especially for those that are on machines with 4GB or even 8GB of RAM, it means that everything is going to run slower, especially if you have a number of tabs open.
Reis did also note that the team is working to reduce the load in future updates, so this could just be a temporary issue for those that are using Chrome right now. Chrome is going to increase its RAM usage across Windows, Mac and Chrome OS, unfortunately, but it is to keep users safe from these exploits, especially Spectre which is the bigger exploit here. You can check out the full blog post from the Chrome team in the source link below, where the team explains everything that is new here, and why Chrome is going to eat up more of your RAM.