What we need first is a table in your SSRS package, having created your data connection and dataset. Dataset being the data you wish to display in the table.

Add the details you wish to see in the table into the table in design mode this will not show the data just the dataset detail name.

Once you have all the details in the table where you want them we can start adding groupings.

There are two types of groupings called Parent and Child groupings and these can be added at two levels either Row Groups or Column Groups.

If we take the Row Groups for example once data has been added to the table there will be an entry here for Details.
Now if we right click on Details we will have a context menu show with a number of options one of them being Add Group. This is the option we need to hover over which will show another context menu with our grouping options.

Here we if we select Parent Group we can then select an item from our dataset to group by, what this means is that all the data in the table will have a Parent Level grouping of that particular dataset.

When we preview the table it now shows the Parent Group as a column on the left-hand side of the table (grouping to an SSRS table) and the details in columns and rows to the right-hand side of the parent group.

A child group would be added as a group of the parent group in much the same way as adding a Parent Group we would actually select child group instead. We can then select a dataset item to have as a group.

This data would then show next to the parent group but before the details, then groups can be set to be expanded if needs be to tidy up the table.

Column groups will be added in the same way the only difference is that they will act against/as columns and not rows as in the above explanation.