In Firefox you type "%" into the url bar, which will search all tabs.
Also you can right-click the back button to see the history of each tab. Usually that begins with a google search that reminds me what the context was.
I try to keep all tabs for a certain topic in the same window, or two windows if I want to tile them to view both. Obviously, I'm very bad at respecting such limits. :-)
Have often gone at 2K+ (which maybe isn't absurd compared what others have opened) but max ~100 active rest being unloaded. Only issue had once was sidebar went into rendering loop on browser startup. Not sure what did to fix (should've maybe fill a bug report too) but lost the hierarchy so had to group them again. A bit time consuming due to the amount of tabs but not much since you can select and group multiple tabs.
Also you can right-click the back button to see the history of each tab. Usually that begins with a google search that reminds me what the context was.
I try to keep all tabs for a certain topic in the same window, or two windows if I want to tile them to view both. Obviously, I'm very bad at respecting such limits. :-)