[mxvzr]

IMO this attitude (ie. deception) is not okay. Whatever the frequency of it, it sounds dishonest. Besides I think you're overlooking the impact it has on your peers: it is very likely someone with similar skillset will see right through the padded estimates and/or can tell the difference between bogus and actual work. Some may have trouble keeping their heads down once they've figured this out. When uninspired I think it's best to openly admit it and fallback to more menial tasks while you wait for the energy to comes back than to engage in this kind of behavior. Personally I wouldn't put up with it for very long, for fear of seeing it spread to other team members.

[adkv]

Is it going to be encouraging to other team members to be honest in the weekly meeting and tell everyone 'oh I didn't feel in the zone this week so I haven't done any of my tasks'? Aren't they going to think, well I never take a week to have a rest, maybe I should start doing that?

I can't see the boss being fine with this more honest way of handling it either.