When I was in high school many, nay most, of the classrooms in our 80 year old building still had the original desks. I always found these to be really cool and loved being in rooms with them despite the fact that the desks were made for a smaller generation. Notice the cutout for an inkwell in in upper right corner. Back in my dad's day, some of them still had the glass inkwell in them.
Fast forward many years to the start of my own teaching career. My school still had a few rooms of the original furniture but most rooms had desks that looked like this (the one on the right). The benefit of these desks is that they were separate from the chairs and larger students were more comfortable. They could also be moved around for group work or (cooperative learning as the buzz word was back in my day). The draw back was that the pocket under the table top served as a depository for all sorts of garbage. Literally. My last class of the day quickly got into the habit of "dumping" a third of the desks every Friday and all of them right before a long break. Teachers that did not do this often found themselves faced with a mouse jumping out at a kid during class. Eek!
Then the trend turned toward the tablet type of desk (scroll down) because they did not have the garbage-collecting pockets. We buy the big ones but the smaller ones allow for many more kids in a room or, conversely, more room to move around with the same number of kids. The smaller ones, however are really not practical for spreading out papers and such so we have divested our selves of the few we had. Tablet desks are movable but not great for group work. They all have a slight slant to them and are awkward to put together to make larger surfaces. The final drawback is that, like the original fixed desks, they have limited room for the larger student.
It has been part of my job over the last few years to replace the remaining pocket desks with big tablet desks. Just when I was about to complete the conversion (this is done over many years due to the cost of the desks) the trend changed again. Last spring I was asked to order two types of tables. The first is totally new to our school -- the "kidney bean." I remember sitting at a table like this in my "open classroom" in third grade. They are good for group work but I have my concerns about them for testing. The second is a standard table and is multi-functional. Put two together and you have a square with seating for 8. Line them up and make corners and you have a hollow square or a "U" or an "L." Again, not great for testing but not too bad and they have a lot of possibilities. Personally, I like these better then the tablet desks.
What will the next trend be in seating? Will we start hanging the kids from the ceiling or turning them on their sides? Who knows? Only time will tell.