This tilt-top table, once for sale on Rita Bucheit Antiques, was built in 1825 and shows an interesting secret compartment revealed when the top is tilted vertically.
A breakfast nook can contain considerable space for hidden storage. This custom bench by Crown Point has a lift up bench seat and a secret slide-out drawer for bar related items.
This bed frame from IKEA allows the mattress to pivot up and reveal a secret storage area underneath. It makes good use of wasted space, but this concept could be used to custom build a much stronger secure area below your bed. Or I guess you could just get a Bed...