LCR meter weird datasheet
While both capacitors and inductors have a performance that can vary with frequency, the sensitivity of capacitors to frequency is slight to non-existent. The sensitivity of inductors is serious to pathological.
A good LCR meter will not simply tell you what the measurement frequency is, but will measure at several different frequencies, to allow you to see what's happening to the measurement.
Capacitors
At the sort of frequency common LCR meters use (kHz, 10s of kHz), the geometry/inductance of 'most' capacitors is negligible.
The frequency dependent dielectric relaxation effects of most plastics are completely negligible, and you would be hard-pressed to measure the effects of electrolytics in a simple LCR meter.
Inductors
These are generally wound on a magnetic core.
If you use a frequency that's too low, the core will saturate, and the measured inductance will change by orders of magnitude.
If you use a frequency that's too high, the core will become very lossy, which may create a significant reading error, depending on the method the LCR meter uses.