As far as i know, there is no way to view the table structure (DDL's) in ACT. If you have Eclipse configured to connect to your system, you can view these DDL's. However they do not show the distribution key. For the distribution key, there is another query that you will need to fire.
\d schemaname.tablename shows
modifiers for columns
table type (fact/dimention )
storage type ( row / column)
What you cannot see in ACT is partition info. ( I use aqua data studio to check out partitioning)
How ever you can check out partitioning info using nc_all_child_partitions and nc_all_parent_partitions views. ( join with nc_all_tables and nc_all_schemas )