I saw a paint tray that is made of nylon and would like to know if it is suitable to contain paint and will it be harder to clean after painting? (Comparing with paint tray made of plastic and the paint used is either water-based or oil-based paint)
Nylon is a type of plastic.
Most cheap painting brushes are made of nylon. They can withstand the solvents used in the oil painting process.
Since nylon is a family of compounds with different properties, and the paint tray you mention is marketed as such, you can be sure its resistance, durability, and breathability are all within the characteristics of what one can expect from it. It should be as easy to clean as any other plastic tray.