Bench scrapers are straight-sided pieces of metal or plastic. As you probably guessed, they are used to scrape flour or dough off a working surface, but they are also handy for cutting dough when you have to divide a dough ball or piece of dough into smaller pieces. I have 2: an older, wooden-handled one that I still use and a larger, newer all-metal one.
A serrated edge is also called a sawtooth or notched blade. Compare it to a straight edge, on the knives and vegetable peelers below.
A pan that has a removable ring, so that a cake or other item made in the springform can be served on the bottom. The ring is helf tight by a spring, which is released to lift the ring off the bottom. This type of pan does not require the baker/cook to turn the pan over to remove the cake or other item, as you would do with a "normal" pan.
Mortars and pestles are a bowl/club combination used to crush, mash, grind or pound various types of food. They can be made of lots of different materials and in a variety of shapes. Although there are mortars and pestles made of wood, they tend to be made of heavier materials, such as brass, stone, granite, ceramic materials and marble. I have three brass sets and one made from volcanic stone. I use them for mashing avocados and other ingredients for guacamole. I also use them to grind spices that originally come in seeds, like cumin and fennel.
If you don't have a mortar & pestle, you can use a coffee bean grinder to grind spices.