If you book x tickets for men's basketball, then 10-x tickets for table tennis,

1000 x+500( 10-x)= 8000

2x+ 10-x= 16

X=6 (sheets)

Table tennis tickets: 10-x= 10-6=4 (sheets);

(2)

If you book X tickets for men's basketball, X tickets for football and 10-x-x= 10-2x tickets for table tennis.

Buying a table tennis ticket costs less than buying a men's basketball ticket 1000 yuan;

1000 x-500( 10-2x)= 1000

2x- 10+2x=2

4x= 12

X= 12/4=3 (sheets);

10-2x= 10-6=4 (sheets);

Total cost =1000x3+800x3+500x4 = 3000+2400+2000 = 7400 (yuan) < 8000 yuan;

So he can book three tickets for men's basketball, three tickets for football and four tickets for table tennis.