Data Loader cannot handle this implicitly because there is no logical path to follow. In case your Data Loader CSV file for import will contain commas for any of the field content, you will have to enclose the contents within double quotation marks ” “. Data Loader will be able to handle this.
For example :
1
Column_1__c,Column_2__c,Column_3__c
2
Shiva,”Jitendra, Minal”,Soft
If you are creating the import CSV in Excel, the quotation marks will be inserted automatically by Excel whenever a comma is detected in any cell – Saving the CSV in Excel and opening the same in Notepad reveals the enclosing quotation marks for cells containing commas.