All you need is a few items that are most likely laying around your house and you can have yourself lovely Holy week decor and a simple object lesson. Here's some ideas I'm doing this year.
Palm Sunday: Palm branches in center of table (Jesus riding into Jerusalem)
Monday: Little wooden animals & mini buckets of coins tipped over (Jesus clearing the Temple)
Tuesday: Easter Lily or a drawing of an Easter Lily (teaching at the Temple, loving your neighbor)
Wednesday: Jars of oil and sweet smelling candles (Mary washing Jesus feet)
Thursday: 30 pieces of silver (Judas betrayal)
Friday & Saturday: Black tablecloth (death of Christ)
Sunday: Pretty table cover and huge vase of flowers (He is Risen)
The ideas for this is endless, be simple or extravagant.
For more ideas on how to celebrate Holy week each day, go here