As mentioned by @takethel you can use a special passage named StoryCaption to display content in the SugarCube side-bar.
If your $inventory story variable contains defined items like the following
<<set $inventory to {}>>
<<set $inventory.Apple to {
"quantity" : 4,
"description" : "Apple Description"
}>>
<<set $inventory.Banana to {
"quantity" : 4,
"description" : "Banana Description"
}>>
... then you can use the Key & Value format of the range <<for>> macro to loop through each of the defined items like so.
<<for _key, _value range $inventory>>
/* Display the Key and one or more properties of the Value. *
<</for>>
eg. The following uses an unorder list to display the Key and the Quantity of each item.
<<nobr>>
<ul>
<<for _key, _value range $inventory>>
<li>_key (_value.quantity)</li>
<</for>>
</ul>
<</nobr>>
... you can use CSS like the following in your Story Stylesheet area to left align the list.
#story-caption ul {
text-align: left;
}