Almost three years have gone by since the question was asked, but I think my answer could still be current for some people.
I also was curious about the power consumption of modern 2.5" drives but didn't find any good articles except this discussion and the Tom's Hardware article about 500 Gb drives (mentioned in the question). After some further googling, I found the official specification of Seagate Barracuda 2.5" 3/4/5 Tb drives for spinning up/reading/writing/sleep modes.
Since all modern 2.5" HDDs are more or less the same in their implementation, we can use this specification as a reference. Keep in mind though, that other drives could have a deviation of up to 20% in comparison to this one (like in the question's table).
For archival purposes, here is an excerpt from the specification:
Typical power measurements are based on an average of drives tested,
under nominal conditions, at 25°C ambient temperature. These power
measurements are done with DIPM enabled.
• Spinup current is measured from the time of power-on to the time
that the drive spindle reaches operating speed.
• Read/Write current is measured with the heads on track, based on
three 64 sector read or write operations every 100 ms.
• The drive supports two idle modes: Active Idle mode and Low Power Idle mode.
┌────────────────────────┬───────────────────────────┐
│ Power Dissipation │ 5TB, 4TB & 3TB models │
│ │ +5V input average (25° C) │
├────────────────────────┼───────────────────────────┤
│ Spinup (max) │ 1.2A (6W) │
├────────────────────────┼───────────────────────────┤
│ Write average │ 2.10W │
├────────────────────────┼───────────────────────────┤
│ Read average │ 1.90W │
├────────────────────────┼───────────────────────────┤
│ Idle, low power mode │ 0.85W │
├────────────────────────┼───────────────────────────┤
│ Standby/sleep │ 0.18W │
└────────────────────────┴───────────────────────────┘
Standby power is measured at steady state (after 200ms from transition)
P.S.: I'm not affiliated with Seagate in any way.