[cema]

  I'd rather see "waiting tables" rather than nothing

But why? Maybe the person used that time to study technologies, to update her skill set. Maybe she used that time to relax and get a long deserved vacation. (Or a myriad other possibilities.) What is wrong with that?

[reitanqild]

If somebody set aside 3 months to study something they should write that. Otherwise it loos like they've been unemployed, in jail or something they rather don't want to talk about.

Also I read it as multiple 3 months gaps. I might have misread though.