Table height for a datatable

Question

I am trying to create an Rmarkdown document that has three datatables next to each other. One has more rows than the others. I would love all three tables to have the same height if its possible. I tried the height parameter in the datatable function, but it has no effect. I also tried putting height into the divs which also did not work. I found online how one may adjust row height using the rowCallback option, however, this does not help. And by the way I only would like the tables to occupy the upper 1/3s of the document, i.e. not make them fill the whole doc height, i.e. reduce the height of the first table on the left. Below code for demo:

library(DT)
dtable = (function(x) datatable(x, options = list(dom = 't'),height=450))

<div class = "row", style = "height:450px;">
<div class = "col-md-4">
```{r ,  warning = FALSE, echo = FALSE, dev=c('svg')}
dtable(fb.summary)
```
</div>
<div class = "col-md-4">
```{r , warning = FALSE, echo=FALSE, dev=c('svg')}
dtable(tw.summary)
```
</div>
<div class = "col-md-4">
```{r , warning = FALSE, echo=FALSE, dev=c('svg')}
dtable(gr.summary)
```
</div>
</div>

And screenshot:

Desired result:

Thanks.