...chrome requires 100-700MB of RAM per tab. It seems that web browsing is the biggest RAM user
Outch! 400MB per tab on average is outrageous!
Also sad, especially now when most browser, including current Mozilla Firefox, are Chrome based. Let's see, how much RAM to buy for 818 tabs in 77 windows?
818 x 400MB = F.U. Chrome! (about 300GB)
Firefox 54 was managing that many tabs with just a few GB of RAM, without using the swap file. The swap is a 1GB virtual disk kept in RAM, to spare extra SSD writings.