Do you mean you can't "zero" the group (the table furniture with all the elements on top of it)?
If something I have learnt while building a level is that when you create a folder (ANY folder, doesn't matter if GROUP or plain FOLDER), if you drag it directly onto the hierarchy it will land on (0,0,0) for that asset or merged assets. However, if you move the elements WITHIN that folder in bulk (by selecting all of them manually on the viewer or from the hierarchy) and then you click the folder that contains all the elements you moved before, the folder will still has (0,0,0) transform, but the elements within it will have the customized offset you gave them before.
I personally use the folder as anchor to rotate pieces around while still retaining the individual position of each asset within the folder with the offset I like.
At least that is how I understood it myself, because it was trial an error from my part.
I just realized that there is the function for groups
"Reset relative transform, Keep Child World Transform"
by that I can set the Positions of groups to 0,0,0,
but it does NOT help me to get the objects ( of the pancake ) to "zero" ),
Objects within groups, I have to set manually to the new destination. Best is to remind the coordinates of the now zeroed position of the group / folder, as base for a coordinate update of the objects within a zeroed group / folder.
Ok this will prevent me from putting objects into the graphical game preview, better to put it into groups in the explorer tree, and then from there into the game preview...