Sp_help provides a lot of information about the structure of the tables inside your database. You can highlight a table name in the SQL Query editor and then press the Alt + F1 key combination or you could type a command such as the following:
sp_help 'TableName'
This will produce a few results, including the following:
Table name with its creation date
Table columns with their respective datatypes
Primary Key information
Index information
Constraint information
