There are two types of objects in SAP, client dependent and client independent. Objects used in several clients are called client independent while objects used in a specific client is called client dependent. To identify if a table is client dependent, one can use tcodes SE11 or SE12. In the table field attributes, if the MANDT field is present that table is client dependent.

A flag of client dependent or independent is saved in table dd02l when the table is activated.

The accurate logic is: if the domain type of 1st keyfield is 'CLNT', the table is client dependent, otherwise it is client independent.

The domain type of domain "MANDT" is defined as "CLNT". But you can define a same kind of domain yourself