It is not uncommon in Byzantine texts to see the term Altar used to refer to the sanctuary, that is, everything inside the iconostas, while the Holy Table and the table of preparation are both sometimes called altars.
The Holy Table is devoid of visual references to the death and entombment of the Body of Christ, save when the antimension is opened; it serves, like all other icons, as a tool for teaching the faith and prompting the memory of the faithful. Further, the Antimension is the license from the bishop to say the divine liturgy; as an Icon, it reminds of the sacrifice which is offered: the death (and thus the subsequent resurrection) of Christ.
The actual first work of salvation occurs while the mortal body of Christ was dead: the opening of the gates of sheol, and the righteous dead of the Old Covenant being lead out of Sheol. Even the thief going to paradise. All of these occur with the death of Jesus upon the cross; the sign of that death is the taking down of the body and/or the placement of the body into the tomb.
Note that the Tomb itself is present on the Holy Table at almost all times, in the form of the Tabernacle, but it is itself not a visual tomb, but a Church or tent in miniature, or a sign of the holy spirit (a dove). Signs of the life within, and a reminder of the focus of the church as a home for Christ, where we come to be close to him and grow closer, being in the presence of the body of Christ. But it also is where the body is laid to rest, and that body is not living in the sense of a mortal human body, but still, it is laid to rest within the tomb, to be brought out of the tomb to bring salvation when needed, as Christ himself brought salvation to the living by his resurrection.*
*it can be argued his death is the point of salvation, but us mortals needed the resurrection to prove it to us as a generality.
It’s a multifold symbolism.