This modern design table legs with moderate strength and be practicable use.
The leg were designed with heights of 100 and 200 mm. Need 3 screws for each leg.

100mm Leg require:

• Recommended diagonal of the top board at least 210 mm.
• Need 3 screws for each leg. The holes have a diameter of 3.3mm, the blind hole 6.6mm.

200mm Leg require:

• Recommended diagonal of the top board at least 420 mm.
• Need 3 screws for each leg. The holes have a diameter of 5.4mm, the blind hole 10.8mm.

Print Settings:

• Material: PLA, PETG
• Layer height: 0.3mm
• Supports: No
• Perimeters: 2 (Increase according to the required toughness.)
• Infill: 15% (Increase according to the required toughness.)

Assembly: 

• Place the table legs on the diagonal of the board.
• Temporarily tightening the screws near the center of the board.
• Install the screws on the outside of the board and tighten the screws on the inside as well.