Q:

Why are tables pluralised in linq-to-sql? 

All the table names are appended with a 's'? 
Like table test will appear as tests in the coding. 
Is this a known bug? 

A:

Its not a bug, its a feature of LinqToSql called pluralization - you can disable it by reading the following Stackoverflow topic:
Linq to SQL: How do I stop the auto generated object name from being renamed?