katuday:
I am very new to D.
Welcome to D :-)
alias the_row = string[]; alias the_table = the_row[];
Here you are defining two types (and in D idiomatically types are written in CamelCase, so TheRow and TheTable).
File inFile = File("account.txt", "r");
This is enough: auto inFile = File("account.txt", "r");
while (!inFile.eof()) { string row_in = chomp(inFile.readln());
This should be better (untested): foreach (rawLine; inFile.byLine) { auto row = rawLine.chomp.idup.split("\t");
the_table ~= row_out; //Error: string[][] is not an lvalue
theTable is not a variable, it's a type, so you need to define it like this:
string[][] table; Bye, bearophile