Answer: AV1 is a personal avatar for children suffering from long-term illness, helping them to continue their education and maintain the normality of daily life despite no longer being able to access mainstream education. Through an app, the user can remotely log into the class from their home or hospital. Looking through the robots eyes, the child can watch the lesson, through the robot’s ears they can hear greetings from their friends and they can speak through the robot to interact with the rest of the class.

Answer: These are emergency showers. An affected person (chemical spills, laboratory mishaps, etc) will pull the level on the top and tepid water (OSHA defined between 60F and 100F) will douse the affected from the shower head (above) and boot sprayer (below). The duration of these showers is required to be 15 full minutes at approximately 20 PSI.
Source: I design these systems.

Answer: So water doesn't stay on the bottom if you put the mug in the dishwasher and stops wet mugs suctioning themselves to coasters.
Pretty clever design actually.

Answer: a practice gravestone scrap. Someone who carved gravestones would practice engraving lettering and drawings on this broken piece of stone.

Answer: Fabulous antique early Victorian chatelaine aide memoir from mid 1800s. Made of sheets of bone, it would have hung on a lady's chatalaine chain or been kept securely in her pocket and she would have used it to make note and appointments for the week to come. It has 6 pages for the days Monday to Saturday, of course a lady would never have made appointments on a Sunday

Answer: Settling pond for erosion control and improving the downstream water for happier fish

Answer: Termite poop.

Answer: "It is a wave-powered desalinator that is owned by Oneka Technologies, a firm in Quebec. It takes seawater and turns it into fresh water. It is powered by the motion of the waves."

Answer: Hag moth caterpillar with fuzzy “false arms” on its back to make it look like a dead leaf. (We’re looking at the belly)

Answer: The white block to the left is made with cashew nuts and sugar : It is called kaju barfi. The yellow block looks like it is mango flavored barfi. The circular one looks like dried fig with nuts stuffed in it. The shiny ones have edible silver foil and are also made from almonds, cashews and pistachio nuts. They are all made with clarified butter and are delicious desserts.

Answer: Patient had been tased. It's a taser dart.

Answer: It's an anti-theft device for pocket watches.

Answer: There was recently a Chinese Long March 3B rocket launch that failed, and the rocket and its payload was seen reentering the atmosphere near Guam

Answer: Checked the tax records... It is or was an alligator farm.

Answer: It's a fridge, or a old time cold room. Basically a room covered with dirt for insulation

Answer: Aztec calendar. Funny thing, I remember a bunch of these a while ago being smuggled over the border and they were made of meth.

Answer: For doing surgery on the cow

Answer: Stonefly larvae. Good sign for the water quality.

Answer: It's potato art... And I'm not even kidding... The artist is unknown (some say by an artist called NoNose), if you look for 'London bus stop potato art' you can find many more articles written about it.

Answer: Those are the studs from your walls -- redistributed by your termites.

Answer: Jar opener

Answer: A rainbow is a rainbow. The cause is refraction/dispersion of light due to water in the air.
Looks like it’s raining over there. The shape is just a matter of angles and height.

Answer: Flying buttresses. They’re there to transfer the weight of the roof outwards to stop the walls bowing and collapsing.

Answer: Hoof pick for cleaning horses hooves.

Answer: Sea grass ball

Answer: Skateboard prevention device. Keeps em from grinding on edges.

Answer: Magic square. It's a popular sort of decoration to put outside math departments

Answer: It is an underwater mine

Answer: It's a razor blade sharpener. A 1930s salesman's special and it doesn't even sharpen the blades just realigns the edge and gets you a few more shaves.

Answer: This label is used for materials with gamma and neutron emissions This label was specifically used on containers shipped by aircraft, and that reference is from the late 50s/early 60s. Any red label is going to be Group I or II, which as stated above emits gamma rays, neutrons, or both, and is potentially harmful even with the box closed. OP's lid came from something shipped by air, but it's interesting to note that on ground shipments of the same class of materials (like with the label variant I found in my first edit), the trucks themselves were required to be marked "CAUTION" or "DANGEROUS - RADIOACTIVE MATERIALS" on the sides and rear of the vehicle just to haul this kind of material.
Post author update: As of today a 3 man team from the state of Utah department of environmental quality, division of waste management and radiation control, uranium Mills and radioactive materials section (holy [crap]) showed up at my friend's house around 10am and spent a few hours taking readings, swabbing samples and asking questions and after all of that, found nothing but natural trace amounts of radon. The "lid" they think was from the late 1950's and was unrelated to the "vault".

Answer: That’s a bacteria pellicle.