No, that's not what it means, that's why I asked if you meant for EM waves.
While yes, all matter does have an associated wavelength, but no, you can't compare the rest mass energy to the energy for an EM wave.
You should read about http://en.wikipedia.org/wiki/Wave-particle_duality" if you are curious.
For photons, [tex]E=h f[/tex] where the momentum of a photon is given by,
[tex]p = {E \over c}[/tex]
Generalized to massive particles, we get
[tex]\lambda = {h \over p}[/tex]
Where [tex]\lambda[/tex] is the associated wavelength.
In general, energy is not just the rest mass energy and also includes a momentum term, so for our massive particles we have: [tex]E^2 = m^2 c^4 + p^2 c^2[/tex]