The three zones within the Mishkan; the Chatzar (courtyard), the Kodesh and the Kodesh Hakodoshim, represent three different experiences in which we serve Hashem.
The courtyard was where the Altar was located. The Avodah of Korbanos was a daily service, performed even on weekdays. This represents our service of Hashem in the mundane where we seek to elevate the physical world - like the elevation of the coarse meat of the sacrifices.
The Shulchan was located in the Kodesh. On Shabbos, the Lechem Hapanim would be placed on the Shulchan. Like Shabbos, this represents times of spiritual inspiration and upliftment. Whilst we take a step out of the mundane, we still maintain involvement with physicality such as the Shabbos meals. This is represented by the more refined Lechem Hapanim.
The Kodesh Hakodoshim was only entered once a year on Yom Kippur. Unlike the Korbanos and the Lechem Hapanim, in the Kodesh Hakodoshim, the Kohen Gadol burned incense, something that only benefits the soul.
This represents moments of heightened spiritual experience where we transcend physicality and rise above worldliness completely. This is like the experience of Yom Kippur, where we refrain from eating as we soar beyond the limitations of our body and connect deeply with our soul.
From time-to-time we need the Yom Kippur experience. More frequently we need the upliftment of the Shabbos experience. But our primary service of Hashem, the day-in-day-out, is connecting to Him in the courtyard of our mundane.
~ Reshimas Hamenora 13