Most household junk and construction debris is fine to load. The limits come from Florida law and from what the Solid Waste Authority accepts.
Florida doesn't allow lead-acid batteries, used oil, or white goods such as refrigerators, washers, and water heaters to go into landfills. Some yard waste is restricted too. Keep these out of your dumpster.
The usual exclusions apply as well. Don't load hazardous waste, liquids, paint, solvents, fuel, or asbestos. The Town notes that paint, pesticides, pool chemicals, antifreeze, and engine oil need special handling, and the Solid Waste Authority runs a Home Chemical & Recycling Center for them.
If you have an item you're unsure about, ask your account manager before you load it.