How to insert smooth table in R markdown presentations slidy, ioslides or beamer

I am preparing an R markdown presentation, but I couldn't find how to arrange table view. For example all numbers are left alligned.

Is there an easy way to arrange R markdown tables? And could anyone suggest an advanced resource on R markdown presentations?

Thanks in advance

I find the resources on the Rmarkdown website to be quite good. The example below shows how to do alignment of simple tables.

 Right      Left     Center     Default
-------     ------ ----------   -------
     12     12        12            12
    123     123       123          123
      1     1          1             1

Table:  Demonstration of simple table syntax.

The headers and table rows must each fit on one line. Column alignments are determined by the position of the header text relative to the dashed line below it:

If the dashed line is flush with the header text on the right side but extends beyond it on the left, the column is right-aligned.
If the dashed line is flush with the header text on the left side but extends beyond it on the right, the column is left-aligned.
If the dashed line extends beyond the header text on both sides, the column is centered.
If the dashed line is flush with the header text on both sides, the default alignment is used (in most cases, this will be left).