Join tiles in Corona SDK into one word for a Breakout game grid?

In the interest of actually answering the question:

I'm not 100% sure what you mean by "How can I join these letters", but from poking through the code I have a guess, so please clarify on whether it is accurate, or if I am wrong about what you wanted.

Scenario 1

You haven't successfully achieved the image illustrated in the screenshot - you've been able to draw one letter, but not multiple ones.

In this case, you'll need to have a better understanding of what your code is doing. The CreateBricksFromTable function takes in a Level object, which is created by the MakeLevel function from a table with a bricks property, which is a table of tables that represent rows with columns in them, showing what type of brick should be at each position. In your commented-out level, you have created an table where the bricks field contains a field for each letter, but the MakeLevel function still expects a bricks field that directly contains the grid of blocks. You will have to - as it seems you attempted - create a MakeWordLevel function (or the like) that takes this letter list, and a word for each line, and constructs a larger grid by copying the appropriate letters into it.

StackOverflow is not your programming tutor, and an SO question is not the right forum for having people write code for you or getting into step-by-step details of how to do this, but I'll leave you a basic outline. Your function would look something like this:

local function MakeWordLevel(data, line1, line2)
    local level = {}
    ...
    return level
end

And then would have to:

• Populate all of the same properties that MakeLevel does
• Calculate how wide (level.columns) the level should be with all the letters
• Create a table in the same format as the bricks properties, but big enough to hold all of the letters
• Go through the input strings (line1 and line2), find the correct letter data from what is now the test6 array, and copy that data into the large table
• Assign that table as level.bricks

This question already is a bit outside of what StackOverflow is intended for in that it asks about how to implement a feature rather than achieve a small, specific programming task, so any further followup should take place in a chatroom - perhaps the Hello World room would be helpful.

Scenario 2:

This was my original guess, but after considering and reading past edits, I doubt this is answering the right question

You may want a solid "background" of, say, red blocks, surrounding your letters and making the field into a solid "wall", with the name in a different color. And you may want these bricks to slowly show up a few at a time.

In that case, the main thing you need to do is keep track of what spaces are "taken" by the name bricks. There are many ways to do this, but I would start with a matrix to keep track of that - as big as the final playing field - full of 0's. Then, as you add the bricks for the name, set a 1 at the x,y location in that matrix according to that block's coordinate.

When you want to fill in the background, each time you go to add a block at a coordinate, check that "taken" matrix before trying to add a block - if it's taken (1), then just skip it and move onto the next coordinate.

This works if you're filling in the background blocks sequentially (say, left to right, top to bottom), or if you want to add them randomly. With random, you'd also want to keep updating the "taken" matrix so you don't try to add a block twice.

The random fill-in, however, presents its own problem - it will keep taking longer to fill in as it goes, because it'll find more and more "taken" blocks and have to pick a new one. There are solutions to this, of course, but I won't go too far down that road when I don't know if that's even what you want.

I don't really understand (or read, for that matter) your code but from what I see joining them into complete words is easy. You have two possibilities.

You can "render" them directly into your level/display data, simply copy them to the appropriate places, like this:

-- The level data.
local level = {}

-- Create the level data.
for row = 1, 25, 1 do
    local rowData = {}

    for column = 1, 80, 1 do
        rowData[column] = "."
    end

    level[row] = rowData
end

-- Now let us setup the letters.
local letters = {
    A = {
        {".",".",".","#",".",".",".","."},
        {".",".","#",".","#",".",".","."},
        {".",".","#",".","#",".",".","."},
        {".","#",".",".",".","#",".","."},
        {".","#","#","#","#","#",".","."},
        {"#",".",".",".",".",".","#","."},
        {"#",".",".",".",".",".","#","."},
        {"#",".",".",".",".",".","#","."},
        {"#",".",".",".",".",".","#","."}
    },
    B = {
        {"#","#","#","#",".",".","."},
        {"#",".",".",".","#",".","."},
        {"#",".",".",".","#",".","."},
        {"#",".",".",".","#",".","."},
        {"#","#","#","#",".",".","."},
        {"#",".",".",".","#",".","."},
        {"#",".",".",".",".","#","."},
        {"#",".",".",".",".","#","."},
        {"#","#","#","#","#",".","."}
    }
}

-- The string to print.
local text = "ABBA"

-- Let us insert the data into the level data.
for index = 1, #text, 1 do
    local char = string.sub(text, index, index)
    local charData = letters[char]

    local offset = index * 7

    for row = 1, 9, 1 do
        local rowData = charData[row]

        for column = 1, 7, 1 do
            level[row][offset + column] = rowData[column]
        end
    end
end

-- Print everything
for row = 1, 25, 1 do
    local rowData = level[row]

    for column = 1, 80, 1 do
        io.write(rowData[column])
    end
    print()

end

You save you letters in a lookup table and then copy them, piece by piece, to the level data. Here I replaced the numbers with dots and number signs to make it prettier on the command line.

Alternately to that you can also "render" the words into a prepared buffer and then insert that into the level data by using the same logic.