Defense counsel and his client/Defendant decide where they sit at defense table. There are no rules or laws I know of that say where either has to sit at their designated table. If you have an issue as to where you sit, speak to your counsel about it.
Depends on the county and the court. Each party typically wants to sit closer to the jury. In Montgomery County, the DA and defense attorney have an understanding that on trial day, who ever gets to the table first, is allowed to sit there. The doors open at 7am to both parties.
However, in Houston, the DAs ALWAYS have their desk and computers permanently plugged in at the table closest to the jury. Most Courts won't entertain the arguments of who sits where. There is no law that says one party is allowed to sit at a certain table. But it's just basically understood that the DA has that table, since all of their machinery is hooked up there every day.
If you have a choice, sit at the table closest to the jury and put your client in the seat next to the jury (unless this is a violent offense). It subconsiously shows the jury that your client is not some criminal to be feared and he is right there behaving, listening and interacting with you. It helps personalize your client. If it is a violent offender, best not to push it and put him that close. (just my thoughts)
I like the table next to the jury. They can hear you whispering to the client about strategy or falsities in the evidence. But just remember the jury can hear you.
Traditionally the party with the burden of proof sits closest to the jury. However this is not codified in Texas, therefore whether the State or the Defense sit next to the jury is usually controlled by local rule. As to where a defendant would sit at the defense table is a tactical decision for the lead defense attorney. There is a lot of theater to a trial. If the defendant presents well in front of the jury then perhaps lead counsel will place the defendant in a position where the jury has no problem seeing him. If the defendant is sullen, does not present well, then the lead attorney may want the jury to concentrate on him instead of his client.