SMD capacitor package size and high frequency performance

Yes, it makes a difference.

A larger package will generally have a higher parasitic inductance, leading to a lower self-resonant frequency and higher impedance at high frequencies:

(image source: electronicdesign.com)

For an 0.1 uF capacitor at 0402 size, the resonant frequency is typically in the 10-20 MHz range.

The reason for max ESL is from V=Ldi/dt >> V(ripple)=Vr= ESL * dI/dt where dI comes from CMOS cap load spike with driver ESR 25~50 Ohms into load and Miller Cap in pF with slew time dt and from any CMOS logic drivers, Ic=CdV/dt this is a "dynamic" current spike with Miller cap and input+stray cap loading thus dI(L)=I(C) so ...

Vr=ESL C dV/dt²

Ripple can be large and is critical dependant on ESR ( thus current limit of driver) ESL of track, C load and ESR of C load with high Q resonance. Many variables but in this example 50Ω thus 100mA short circuit current from 5V but only rated for 50mA. with 1 inch of FR4 at 10nH/" and 2pF/" so nearest decoupling cap is 1 DIP package away at 1". The result is > 10% noise but assumes no ground plane.

For ultra low ESL the aspect ratio for L/W must be low. 603, 1206 are both 2:1 but 306 is reverse geometry to 603 and thus nearly 1/4 the inductance and almost twice the SRF.

It is usually best to use 3 caps spread apart by no more than 3 decades due to ESR,SRF properties. The bulk largest size depends on step load & ESR of LDO for load regulation error and the bulk cap reduces this error. Next short term transients > 1us where PSRR is poor is the intermediate cap from 0.1 to 1uF then the smallest cap for RF slew rates values must be >100x the Coss or effective switched capacitance of all synchronous gates in [mA/ns] for charge transformer ratio in ripple reduction. For RF in the GHz range these require careful selection well below 100pF unless sufficiently high rated SRF.

For example of ~40:1 ranges 47uF, 1uF, 0.01uF
ALternatives use many (>>10) in parallel with a low aspect ratio of L/W of same value such as 0.1uF of carefully selected low ESL part.

in general, but specifically don't use General purpose caps use low ESR/low ESL and verify layout and specs. Don't guess.

By the way. this 306 has the same size 60 thou termination coductive pads as 1206. This trick to soldering them with a 67 thou tip (1/16) is to quickly tack one side then solder the other then resolder the 1st side with a toothpick holding it down on (abrasively) cleaned pads. This works well for 603 parts as well and 402 is best done with a hot air method with paste. and tool to hold in place if tombstone issues arise...

These are also excellent 1206 Acrylic caps. http://www.digikey.com/product-detail/en/cornell-dubilier-electronics-cde/FCA1206A105M-H3/338-4076-1-ND/5700231