Table in JsStore is an object which contains name of table & columns schema.

Syntax :-

var table1 = {
    name: "table_name",
    columns: {
        column1: { dataType: 'datatype', primaryKey: true },
        column2 : { dataType: 'datatype'},
        ..... ,
        columnN: { dataType: 'datatype' }
    }
}

Example :-

var tblProduct = {
    name: 'Product',
    columns: {
        // Here "Id" is name of column 
        Id:{ primaryKey: true, autoIncrement: true },
        ItemName:  { notNull: true, dataType: "string" },
        Price:  { notNull: true, dataType: "number" },
        Quantity : { notNull: true, dataType: "number" }
    }
};

Note :- We strongly recommend to create a primary key for every table.

For more information about column - please check column doc.