Common setting options across visuals

First up - make sure you've skimmed the common setting options across visuals in Creating Visuals.

Variable axis

This sets whether your variables are displayed as rows or as columns.

Rows / Columns

These let you define which dimensions (e.g. categories, scenarios, versions) to include as the rows and columns of the table. By default, Time is included as a column dimension.
If your model has its own custom dimensions, you can choose to include those. When including a custom dimension, you can automatically include dimension totals by hovering over the dimension and clicking the Total button.

Reordering variables

You can easily reorder variables in tables by dragging and dropping them.

Show table groups & sections

If variables are grouped in the spreadsheet workspace, then the table will automatically display these variables under a group heading. If you wish you can toggle this off.
You can also show sections as table headers, however this is off by default. This is useful if you have a structured table you need to organise. The hierarchy will show Section, Group, Variable.
Find these settings in the advanced section of your table!