A trial judge’s ruling in relation to where an accused sits during his trial is discretionary and entitled to deference. 

R. v. A.C.,2018 ONCA 333 (CanLII) at para. 37.

In every case, the accused’s placement must permit him to make full answer and defence, but the issue is to be assessed on a case-by-case basis, having regard to the interests of a fair trial and courtroom security in the particular circumstances of the case.

R. v. Lalande (1999),1999 CanLII 2388 (ON CA), 138 C.C.C. (3d) 441 (Ont. C.A.);

R. v. A.C., 2018 ONCA 333 (CanLII) at para. 37.

The seriousness of the offence for which the accused is charged is, in and of itself, not a factor to be considered in determining the placement of the accused in the court, as the seriousness of the offence says nothing about security concerns or the interests of a fair trial. 
R. v. A.C., 2018 ONCA 333 (CanLII) at para. 38.
For more see Stuart O’Connell Law Bog, Should the Accused be Permitted to Sit at Counsel Table during his/her Trial?

Stuart O’Connell, O’Connell Law Group, www.leadersinlaw.ca (all rights reserved to author).