The novel Fe87Ce13−xBx(x = 5, 6, 7) metallic glass (MG) ribbons were fabricated in this work. The compositional dependence of glass forming ability (GFA), magnetic and magnetocaloric properties of these ternary MGs, and the mechanism involved was investigated. The GFA and Curie temperature (Tc) of the MG ribbons were found to improve with the boron content, and the peak value of magnetic entropy change (−ΔSmpeak) reaches a maximum of 3.88 J/(kg × K) under 5 T when x = 6. Based on the three results, we designed an amorphous composite that exhibits a table-shape magnetic entropy change (−ΔSm) profile with a rather high average −ΔSm(−ΔSmaverage~3.29 J/(kg × K) under 5 T) from 282.5 K to 320 K, which makes it a potential candidate for the highly efficient refrigerant in a domestic magnetic refrigeration appliance.