Right-clicking on a table in SSMS 2016 includes an option for the ‘Memory Optimization Advisor’. This starts a wizard to assist in migrating a table to an In-Memory table structure. If the base table has any issues that would prevent it from being migrated to an in-memory structure, the wizard will identify and help to resolve those issues. Here’s a link to some issues that would prevent the migration.
A big issue will be tables with foreign keys defined. The keys will have to be dropped and then re-created, they won’t be migrated.
If all checks pass, then the table can be migrated. There is an option to migrate the data as well.

I posted on In-Memory tables for SQL Server 2014, although several changes were made for 2016. 2016 supports foreign keys, check contraints, outer joins, among other features.